[HN Gopher] The AMD Radeon Instinct MI300A's Giant Memory Subsystem
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       The AMD Radeon Instinct MI300A's Giant Memory Subsystem
        
       Author : pella
       Score  : 207 points
       Date   : 2025-01-18 12:28 UTC (1 days ago)
        
 (HTM) web link (chipsandcheese.com)
 (TXT) w3m dump (chipsandcheese.com)
        
       | amelius wrote:
       | I'm curious why this space hasn't been patented to death.
        
         | hedora wrote:
         | It has been. All sides have a pile of patents. All sides
         | violate all the other sides' patents. If anyone sues, everyone
         | goes out of business.
         | 
         | This is the system working as currently intended. No matter
         | what happens, the lawyers get will rich.
         | 
         | If a small company comes in and doesn't pay the lawyers, it'll
         | get sued for violating the patents.
        
           | yvdriess wrote:
           | Yep, it's an area denial weapon.
           | 
           | You basically cannot do anything worthwhile in this space
           | without violating someone's patents. It's beneficial patent
           | and corporate lawyers, but it's detrimental to innovation. As
           | an engineer you are asked to not look up existing techniques
           | or designs as this will taint you legally.
        
             | kmeisthax wrote:
             | "Tainting" isn't a thing in patent law. All engineers
             | worldwide are tainted the moment the patent is published;
             | that's why parallel reinvention is not a defense to patent
             | infringement.
        
               | lhl wrote:
               | But you pay triple damages if you knowingly vs
               | unknowingly violate a patent (35 U.S.C. SS 284). Of
               | course, everything is patented, so, engineers are just
               | told to not read patents.
        
           | amelius wrote:
           | > If a small company comes in and doesn't pay the lawyers,
           | it'll get sued for violating the patents.
           | 
           | This assumes the small company isn't just in it for the
           | patents.
        
           | WithinReason wrote:
           | Mutually assured destruction
        
             | amelius wrote:
             | Where do patent-trolls fit in this analogy?
        
               | twasold wrote:
               | They're the backstreet gangs that rob single missile
               | silos from failing states and ransom you.
        
       | btown wrote:
       | I've often thought that one of the places AMD could distinguish
       | itself from NVIDIA is bringing significantly higher amounts of
       | VRAM (or memory systems that are as performant as what we
       | currently know as VRAM) to the consumer space.
       | 
       | A card with a fraction of the FLOPS of cutting-edge graphics
       | cards (and ideally proportionally less power consumption), but
       | with 64-128GB VRAM-equivalent, would be a gamechanger for letting
       | people experiment with large multi-modal models, and seriously
       | incentivize researchers to build the next generation of tensor
       | abstraction libraries for both CUDA and ROCm/HIP. And for gaming,
       | you could break new grounds on high-resolution textures. AMD
       | would be back in the game.
       | 
       | Of course, if it's not real VRAM, it needs to be at least
       | somewhat close on the latency and bandwidth front, so let's pop
       | on over and see what's happening in this article...
       | 
       | > An Infinity Cache hit has a load-to-use latency of over 140 ns.
       | Even DRAM on the AMD Ryzen 9 7950X3D shows less latency. Missing
       | Infinity Cache of course drives latency up even higher, to a
       | staggering 227 ns. HBM stands for High Bandwidth Memory, not low
       | latency memory, and it shows.
       | 
       | Welp. Guess my wish isn't coming true today.
        
         | formerly_proven wrote:
         | Totally normal latencies for a GPU though.
        
         | pkroll wrote:
         | You're not the only one thinking that:
         | https://www.nvidia.com/en-us/project-digits/
         | 
         | 128G of unified memory. $3K. Throw ollama and ComfyUI on that
         | sucker and things could get interesting. The question is how
         | much slower than a 5090, is this gonna be? The memory bandwidth
         | isn't going to match a 512 bit bus.
        
           | lostmsu wrote:
           | AFAIK this uses even slower memory.
        
             | sroussey wrote:
             | And a fraction of the 5090 cores.
        
           | manojlds wrote:
           | It's LPDDR5.
        
             | ein0p wrote:
             | That's actually a good thing. That's how you get a ton of
             | DRAM without it costing a fortune. M2 Ultra is able to get
             | GPU-like 800GB/sec with DDR4. From that it follows that if
             | you can design a specialized chip, you can get a
             | respectable 1 TB/sec quite easily with LPDDR5, provided
             | that you're willing to design a chip to support a ton of
             | memory channels (and potentially also a wider memory bus).
             | In fact, I'm baffled that such devices don't already exist
             | outside Apple's product line. Seems like a rather obvious
             | thing to do, and Apple has a "proof of concept" already. I
             | can think of at least four companies off the top of my head
             | that could do it quite easily, besides Apple.
        
           | KeplerBoy wrote:
           | It's going to be waaay slower than a 5090. We're looking at
           | something like 60W TDP for the entire system vs 600W for a
           | 5090 GPU.
           | 
           | It's going to be very energy efficient, it will get plenty of
           | flops, but they won't be able to cheat physics.
        
           | Keyframe wrote:
           | I think digits is STARTS AT $3k. We'll see.
        
         | mpercival531 wrote:
         | They are. Strix Halo is going after that same space of Apple M4
         | Pro/Max where it is currently unchallenged. Pairing it with two
         | 64GB LPCAMM2 modules will get you there.
         | 
         | Edit: The problem with AMD is less the hardware offerings, but
         | more that their compute software stack historically tends to
         | handwave or be very slow with consumer GPU support -- even more
         | so with their APUs. Maybe the advent of MI300A will change the
         | equation, maybe not.
        
           | lhl wrote:
           | I don't know of any non-soldered memory Strix Halo devices,
           | but both HP and Asus have announced 128GB SKUs (availability
           | unknown).
           | 
           | For LLM inference, basically everything works w/ ROCm on
           | RDNA3 now (well, Flash Attention is via Triton and doesn't
           | have support for SWA and some other stuff; also I mostly test
           | on Linux, although I did check that the new WSL2 support
           | works). I've tested some older APUs w/ basic benchmarking as
           | well. Notes here for those interested: https://llm-
           | tracker.info/howto/AMD-GPUs
        
             | UncleOxidant wrote:
             | Thanks for that link. I'm interested in either getting the
             | HP Mini Z1 G1a or an NVidia Digits for LLM experimentation.
             | The obvious advantage for the Digits is the CUDA ecosystem
             | is much more tried & true for that kind of thing. But the
             | disadvantage is trying to use it as a replacement for my
             | current PC as well as the fact that it's going to run an
             | already old version of Ubuntu (22.04) and you're dependent
             | on Nvidia for updates.
        
               | lhl wrote:
               | Yeah, I think anyone w/ old Jetsons knows what it's like
               | to be left high and dry by Nvidia's embedded software
               | support. Older models are basically just ewaste. Since
               | the Digits won't be out until May, I guess there's enough
               | time to wait and see - at least to get a sense of what
               | the actual specs are. I have a feeling the FP16 TFLOPS
               | and the MBW are going to be much lower than what people
               | have been hyping themselves up for.
               | 
               | Sadly, my feeling is that the big Strix Halo SKUs (which
               | have no scheduled release dates) aren't going to be
               | competitively priced (they're likely to be at a big
               | FLOPS/real-world performance disadvantage, and there's
               | still the PITA factor), but there is something appealing
               | about about the do-it-all aspect of it.
        
               | rbanffy wrote:
               | DIGITS looks like a serious attempt, but they don't have
               | too much of an incentive to have people developing for
               | older hardware. I wouldn't expect them to supor it for
               | more than five years. At least the underlying Ubuntu will
               | last more than that and provide a viable work environment
               | far beyond the time it gets really boring.
        
               | UncleOxidant wrote:
               | If only they could get their changes upstreamed to Ubuntu
               | (and possible kernel mods upstreamed), then we wouldn't
               | have to worry about it.
        
               | rbanffy wrote:
               | Getting their kernel mods upstreamed is very unlikely,
               | but they might provide just enough you can build a new
               | kernel with the same major version number.
        
               | KeplerBoy wrote:
               | Who said anything about Ubuntu 22.04? I mean sure that's
               | the newest release current jetpack comes with, but I'd be
               | surprised if they shipped digits with that.
        
               | rbanffy wrote:
               | Doesn't DGX OS use the latest LTS version? Current should
               | be 24.04.
        
               | KeplerBoy wrote:
               | I wouldn't know. I only work with workstation or jetson
               | stuff.
               | 
               | The DGX documentation and downloads aren't public afaik.
               | 
               | Edit: Nevermind, some information about DGX is public and
               | they really are on 22.04, but oh well, the deep learning
               | stack is guaranteed to run.
               | 
               | https://docs.nvidia.com/base-os/too
        
           | Dylan16807 wrote:
           | > Pairing it with two 64GB LPCAMM2 modules will get you
           | there.
           | 
           | It gets you closer for sure. But while ~250GB/s is a whole
           | lot better than SO-DIMMs at ~100GB/s, the new mid-tier GPUs
           | are probably more like 640-900GB/s.
        
         | Fade_Dance wrote:
         | Assuming we are comparing chips that are using the latest
         | generation/high density memory modules, a wider bus width is
         | required for larger memory counts, which is expensive when it
         | comes to silicon area. Therefore, if AMD is willing to boost up
         | memory count as a competitive advantage, they may as well also
         | consider using that die space for more logic gates as well.
         | It's a set of trade-offs and an optimization problem to some
         | degree.
         | 
         | That said, when an incumbent has a leadership advantage, one of
         | the obvious ways to boost profit is to slash the memory bus
         | width, and then a competitor can come in and bring it up a bit
         | and have a competitive offering. The industry has certainly
         | seen this pattern many times. But as far as AMD coming in and
         | using gigantic memory counts as a competitive advantage? You
         | have to keep in mind the die space constraints.
         | 
         | Well over a decade ago - I think it was R600 - AMD did take
         | this approach, and it was fairly disastrous because the logic
         | performance of the chip wasn't good enough while the die was
         | too big and hot and yields were too low. They didn't strike the
         | right balance and sacrificed too much for a 512-bit memory bus.
         | 
         | AMD has also tried to sidestep some of these limitations with
         | HBM back when it was new technology, but that didn't work out
         | for them either. They actually would have been better off just
         | increasing bus width and continuing to use the most optimized
         | and cost efficient commodity memory chips in that case.
         | 
         | Data center and such may have a bit more freedom for innovation
         | but the consumer space is definitely stuck on the paradigm of
         | GPU plus nearby mem chips, and going outside of that fence is a
         | huge latency hit.
        
           | amluto wrote:
           | > a wider bus width is required for larger memory counts,
           | which is expensive when it comes to silicon area
           | 
           | I find this constraint to be rather odd. An extra, say, three
           | address bits would add very little space (or latency in a
           | serial protocol) to a memory bus, and the actual problem
           | seems to be that the current generation of memory chips are
           | intended for point-to-point connection.
           | 
           | It seems to me that, if the memory vendors aren't building
           | physically larger, higher capacity chips, then any of the
           | major players (AMD, Nvidia, Intel, whoever else is in this
           | field right now) could kludge around it with a multiplexer. A
           | multiplexer would need to be somewhat large, but its job
           | would be simple enough that it should be doable with an
           | older, cheaper process and without using entirely
           | unreasonable amounts of power.
           | 
           | So my assumption is this is mostly an economic issue. The
           | vendors don't think it's worthwhile to do this.
        
             | sroussey wrote:
             | Bus width they are talking about are multiples of 128. I
             | think Apple m series chips are good examples. They go from
             | 128 to 256 to 512 bits which just happens to be roughly
             | about the megabytes per second bandwidth.
        
             | formerly_proven wrote:
             | GDDR has been point-to-point since... I dunno, probably
             | 2000? Because cet par you can't really have an actual _bus_
             | when you chase maximum bandwidth. Even the double-sided
             | layouts (like T-layout, with  <2mm stubs) typically incur a
             | reduction in data rate. These also dissipate a fair amount
             | of heat, you're looking at around 5-8 W per chip (~6
             | pJ/bit), it's not like you can just stack a bunch of those
             | dies.
             | 
             | > A multiplexer would need to be somewhat large, but its
             | job would be simple enough that it should be doable with an
             | older, cheaper process and without using entirely
             | unreasonable amounts of power.
             | 
             | I don't know what you're basing that on. We're talking
             | about 32 Gbps serdes here. Yes, there's multiplexers even
             | for that. But what good is deciding which memory chip you
             | want to use on boot-up?
        
               | amluto wrote:
               | Not multiplexed on boot -- multiplexed at run time. Build
               | a chip that speaks the GDDR protocol to the host GPU and
               | has 2-4 GDDR channels coming out the other end and
               | aggregates the attached memory at the cost of an extra
               | chip, some latency, some power, and an extra chip. As far
               | as the GPU is concerned, it's an extra large GDDR chip,
               | and it would allow a GPU vendor to squeeze in more RAM
               | without adding more pins to the GPU or needing to route
               | more memory channels directly to it.
               | 
               | (Compare to something like Apple's designs or "Project
               | Digits". Current- and next-gen GPUs have considerably
               | higher memory bandwidth but considerably less memory
               | capacity. Mostly my point is that I think Nvidia or AMD
               | could make a desktop-style GPU with 2-4x the RAM,
               | somewhat worse latency, but otherwise equivalent
               | performance without needing Samsung or another vendor to
               | build higher capacity GDDR chips than currently exist.)
        
           | Dylan16807 wrote:
           | > a wider bus width is required for larger memory counts
           | 
           | Most video cards wire up 32 data pins to each memory chip.
           | But GDDR chips already have full support for running 16 pins
           | to each chip. And DDR commonly goes down to _4_ data pins per
           | chip.
           | 
           | The latest GDDR7 chips are 24Gbit, and at 16 bits each you
           | could fit 48GB onto a nice easy 256 bit bus, with a speed of
           | at least 1TB/s. If you use 384 bits and/or send 8 to each
           | chip, you can cram in so many chips it becomes a matter of
           | _fitting_ everything.
        
         | enragedcacti wrote:
         | > Of course, if it's not real VRAM, it needs to be at least
         | somewhat close on the latency and bandwidth front
         | 
         | It is close to _VRAM_ *, just not close to DRAM on a
         | conventionally designed CPU. This thing is effectively just a
         | GPU that fits in a CPU slot and has CPU cores bolted to the
         | side. This approach has the downside of worse CPU performance
         | and the upsides of orders of magnitude faster CPU<->GPU
         | communication, simpler programming since coherency is handled
         | for you, and access to substantial amounts of high bandwidth
         | memory (up to 512GB with 4 MI300As).
         | 
         | * https://chipsandcheese.com/p/microbenchmarking-nvidias-
         | rtx-4...
        
           | rbanffy wrote:
           | I was curious because given the latencies between the CCXs,
           | the number of NUMA domains seems small.
        
         | 0934u934y9g wrote:
         | The problem with only providing VRAM is that some AI things
         | like real time audio processing under preform significantly
         | because it does not have the equivalent of tensor cores to keep
         | up. There are LLM's that won't run for the same reason. You
         | will have more than enough VRAM but not enough tensor cores.
         | AMD isn't able to compete.
        
         | therealpygon wrote:
         | I wholeheartedly agree. Nvidia is intentionally suppressing the
         | amount of memory on their consumer GPUs to prevent data centers
         | from using consumer cards rather than their far more expensive
         | counterparts. The fact that they used to offer the 3060 with
         | 12GB, but have now pushed the pricing higher and limited many
         | cards to 8GB is a testament to the fact they are. I don't need
         | giga-TOPS with 8-16gb of memory, I'd be perfectly happy with
         | half that speed but with 64gb of memory or more. Even slower
         | memory would be fine. I don't need 1000t/s, but being able to
         | load a reasonable intelligent model even at 50t/s would be
         | great.
        
           | lhl wrote:
           | Getting to 50 tok/s for a big model requires not just memory,
           | but also memory bandwidth. Currently, 1TB/s of MBW will get a
           | 70B Q4 (~40GB) model to about 20-25 tok/s. The good thing is
           | models continue to get smarter - today's 20-30B models beat
           | out last years 70B models on most tasks and the biggest open
           | models like DeepSeek-v3 might have lots of weights, but
           | actually a relatively reasonable # of activations/pass.
           | 
           | You can test out your half the speed but w/ 64GB or more of
           | memory w/ the latest Macs, AMD Strix Halo, or the upcoming
           | Nvidia Digits, though. I suspect by the middle of the year
           | there will be a bunch of options in the ~$3K range.
           | Personally, I think I'd rather go for 2 x 5090s for 64GB of
           | memory at 1.7TB/s than 96 or 128GB w/ only 250GB/s of MBW.
        
             | sroussey wrote:
             | A Mac with that memory will have closer to 500GB/s but your
             | point still stands.
             | 
             | That said, if you just want to play around, having more
             | memory will let you do more interesting things. I'd rather
             | have that option over speed since I won't be doing
             | production inference serving on my laptop.
        
               | lhl wrote:
               | Yeah, the M4 Max actually has pretty decent MBW - 546
               | GB/s (cheapest config is $4.7K on a 14" MBP atm, but
               | maybe there will be a Mac Studio at some point). The big
               | weakness for the Mac is actually the lack of TFLOPS on
               | the GPU - the beefiest maxes out at ~34 FP16 TFLOPS. It
               | makes a lot of use cases super painful, since
               | prefill/prompt processing can take _minutes_ before token
               | generation starts.
        
         | SecretDreams wrote:
         | If, by the grace of tech Jesus, amd gave us such systems at
         | volumes Nvidia would notice, Nvidia would simply then do the
         | same but with a better ecosystem.
         | 
         | The biggest problem for AMD is not that the majority of people
         | want to use AMD. It is that the majority of people want AMD to
         | be more competitive so that Nvidia will be forced to drop
         | prices so that people can afford Nvidia products.
         | 
         | Until this pattern changes, AMD has a big uphill battle. Same
         | for Intel, except Intel is at least seemingly doing great
         | gen/gen improvements in mid/low range consumer GPUs and
         | bringing healthy vram along for the ride.
        
           | holoduke wrote:
           | It can change quickly. Great example is the short domination
           | of the ati 9700 that crushed nvidia for a short while.
        
           | llm_trw wrote:
           | The same could ba said for CPUs from Intel and AMD 5 years
           | ago. Now people, myself included, buy AMD because it is
           | simply the better choice.
        
             | MindSpunk wrote:
             | The difference with AMD and Intel when zen launched is that
             | AMD launched a product that utterly destroyed Intel's line
             | up in productivity workloads. Zen 1 launched with _double_
             | the cores of the competing intel chip at the same price
             | point. The benchmarks were a bloodbath and intel struggled
             | to respond with a competitive product for 4 years. Arguably
             | they still haven't caught up. AMD just brutally out
             | executed Intel.
             | 
             | Doing that to nvidia would be a tall order
        
               | llm_trw wrote:
               | Core wise Intel had the advantage until the last
               | generation or two. The same can be true for gpus, just
               | add a ton more memory and watch them fly off the shelves.
        
               | SecretDreams wrote:
               | Intel P cores still do well against amd zen5. But their
               | stacking cache is chef's kiss.
        
               | mschuster91 wrote:
               | > The same can be true for gpus, just add a ton more
               | memory and watch them fly off the shelves.
               | 
               | Yeah... for datacenters and people attempting to jump on
               | the AI hype train. Meanwhile your everyday regular gamer
               | has _zero_ chance competing for GPUs with the infinite
               | money coffers from AI.
               | 
               | Seriously, the sooner this crazy bubble bursts the
               | better. I thought the shitcoin mining days were bad but
               | at least everyone back then knew the game for GPUs was
               | over once the first Bitcoin ASIC was released, but now?
               | No end in sight and frankly I'm pissed.
        
           | AnthonyMouse wrote:
           | > If, by the grace of tech Jesus, amd gave us such systems at
           | volumes Nvidia would notice, Nvidia would simply then do the
           | same but with a better ecosystem.
           | 
           | Not if they have "a better ecosystem" -- they would continue
           | to charge a premium for that.
           | 
           | Which creates a dilemma for Nvidia. If they would match AMD's
           | pricing, they'd be losing all the money they could get by
           | charging more, which is a ton. Whereas if they charge more,
           | they get more _today_ from the people who pay the premium,
           | but some people are more price sensitive than others, so
           | there are still a lot of people who would buy  "lots of VRAM
           | for less money" from AMD. And soon AMD has a lot of users,
           | improves their software support and the difference disappears
           | entirely.
           | 
           | Forcing the larger competitor into that dilemma is very much
           | to the advantage of the smaller competitor.
        
         | Aurornis wrote:
         | > AMD would be back in the game.
         | 
         | The market for prosumer cards with high VRAM and low FLOPS
         | would be negligibly small. The data center market is massive on
         | one end and the gaming market is big on the other. Casual
         | consumers who just want a lot of VRAM are such a small minority
         | of people that it doesn't matter to the bottom line.
         | 
         | It also wouldn't be financially advantageous to divert RAM
         | chips away from data center production. We don't have a surplus
         | of chips waiting to be installed, so building out high VRAM but
         | affordable cards would only take away from higher margin
         | products in the datacenter space.
        
           | albertzeyer wrote:
           | You might be true for the market.
           | 
           | However, that target audience, those hobby enthusiasts, hobby
           | developers, also university labs with low budget, those are
           | the people who will develop the future open source
           | frameworks, and ultimately/implicitly those are the people
           | who can have a quite big impact on the future development of
           | brand recognition and the open source ecosystem around the
           | hardware. Those people can shape the future trends.
           | 
           | So, only looking at the market, how much units you would sell
           | here, that totally ignores the impact this might have
           | indirectly in the future.
        
             | almostgotcaught wrote:
             | > However, that target audience, those hobby enthusiasts,
             | hobby developers, also university labs with low budget,
             | those are the people who will develop the future open
             | source frameworks,
             | 
             | No they're not. Y'all are deluded. There's a reason why the
             | are only two real DNN frameworks and both of them are
             | developed at the two biggest tech companies in the world.
        
           | jph00 wrote:
           | Actually there's a _lot_ of demand in the AI data center
           | space for such a card, such as for running large mixture of
           | experts (MoE) models -- e.g. DeepSeek v3, which is one of the
           | best LLMs in the world today.
           | 
           | Although AMD would need to greatly improve their entire
           | software stack to make running AI models on AMD an attractive
           | proposition.
        
           | bsder wrote:
           | > The market for prosumer cards with high VRAM and low FLOPS
           | would be negligibly small.
           | 
           | I don't agree. I regularly get VSCode crashing because it ran
           | out of VRAM.
           | 
           | 8GB VRAM starts to feel cramped when you have to composite
           | multiple web browsers (aka Electron apps) onto your 4K
           | monitor screen.
           | 
           | nVidia not offering 16GB on consumer level cards is purely a
           | market segmentation strategy and AMD should make them pay for
           | it.
        
           | kouteiheika wrote:
           | > The market for prosumer cards with high VRAM and low FLOPS
           | would be negligibly small. The data center market is massive
           | on one end and the gaming market is big on the other. Casual
           | consumers who just want a lot of VRAM are such a small
           | minority of people that it doesn't matter to the bottom line.
           | 
           | I'm sure this is also what AMD is thinking, and it's also why
           | they will never catch up to NVidia in ecosystem and software
           | support.
           | 
           | It's not for the casual consumers, and it's not supposed to
           | make money directly! You want these high VRAM SKUs to attract
           | enthusiast and researchers. I have read a staggering amount
           | of research papers where the authors used some random
           | _consumer_ NVidia GPU. Do you know how many I 've read which
           | used AMD GPUs? Big fat ZERO! You want to incentivize these
           | people to use your hardware? You want to get devs to support
           | your platform? Give them a unique value proposition that the
           | competition won't.
           | 
           | I'm currently waiting for the 5090 to be available, and I'm
           | going to buy two of them. If AMD would have released a GPU at
           | a fair price, with reasonable performance and double the VRAM
           | that NVidia offers, do you know what would I do? I would buy
           | two AMD cards instead, port my software to it, and contribute
           | PRs to any upstream software that I use so that it works with
           | these cards. But alas, here we are.
        
             | almostgotcaught wrote:
             | > You want these high VRAM SKUs to attract enthusiast and
             | researchers. I have read a staggering amount of research
             | papers where the authors used some random consumer NVidia
             | GPU. Do you know how many I've read which used AMD GPUs?
             | Big fat ZERO!
             | 
             | I'm just sitting here wondering how you think this affects
             | anything? Enterprise doesn't buy DC cards based on research
             | papers so why does it matter if research papers are or
             | aren't written against one brand or the other.
        
         | treesciencebot wrote:
         | For traditional LLMs this might be true (especially large MoEs
         | at bs=1) but I highly disagree with "multi-modal models" phrase
         | since most of the models that _output_ in other modalities are
         | generally compute bound. Which means less flops will make the
         | experience so much worse (imagine waiting a couple minutes for
         | an image and hours for videos).
        
       | neuroelectron wrote:
       | >Still, core to core transfers are very rare in practice. I
       | consider core to core latency test results to be just about
       | irrelevant to application performance. I'm only showing test
       | results here to explain the system topology.
       | 
       | How exactly are "applications" developed for this? Or is that all
       | proprietary knowledge? TinyBox has resorted to writing their own
       | drivers for 7900 XTX
        
         | latchkey wrote:
         | ROCm is the stack that people write code against to talk to AMD
         | hardware.
         | 
         | George wrote some incomplete non-perfomant drivers for a
         | consumer grade product. Certainly not an easy task, but it also
         | isn't something that most people would use. George just makes
         | loud noises to get attention, but few in the HPC industry pay
         | any attention to him.
        
           | tucnak wrote:
           | Nobody cares what HPC industry has to say; until recently,
           | they have happily been jerking off Monte-Carlo simulations on
           | overpriced nation-grade supercomputer NUMA clusters and
           | didn't know what a "GPU" was anyway! Also please stop
           | spreading "consumer grade product" propaganda. I had used AMD
           | Instinct MI50's--supposedly datacenter-grade hardware, and
           | have faced the _exact_ same problems as George. Except in my
           | case there was no call-line at Lisa 's.
           | 
           | Guess what, the AI industry has spoken: hyper-scalers would
           | buy NVIDIA, or rather design their own silicon. Any thing,
           | any how, but nothing to do with AMD.
           | 
           | Also: if your business is doing so great, how come you're
           | constantly in all these Hacker News threads talking and
           | talking and talking but not actually releasing products of
           | any kind, of any bread, that any of the hackers on here could
           | use?
        
             | latchkey wrote:
             | > but not actually releasing products of any kind, of any
             | bread, that any of the hackers on here could use?
             | 
             | Our "product" is open access to a very specific type of HPC
             | compute that previously was locked up and only available to
             | a short list of researchers.
             | 
             | Thanks for asking, we just added 1 GPU / 1 minute docker
             | container access through our excellent partners:
             | https://shadeform.ai
             | 
             | 1 GPU / 1 VM / 1 minute is coming soon.
        
               | tucnak wrote:
               | From the looks of it, YOU ARE the product. That is,
               | manufacturing optics of a "partner" and "distributer"
               | ecosystem for AMD. And on borrowed time, too.
        
               | latchkey wrote:
               | > From the looks of it, YOU ARE the product.
               | 
               | Sweet, thanks! That's at least part of what a CEO is
               | supposed to be.
        
               | tucnak wrote:
               | Please don't be salty; the only person here who may
               | embarrass you is yourself. I'm happy that you like to
               | think about yourself as CEO, but perhaps it's worth
               | reflecting you may be doing a better job if you had spent
               | less time on Hacker News, and more time figuring out how
               | to get Hacker News excited about your product? So far you
               | have pledged allegiance to AMD every chance you got, and
               | spun tall tales of great capability, with not much to
               | show for it besides "partners." You know nobody has
               | trained a thing with your GPU's yet? That would be a
               | great place to start for a CEO. To make something people
               | would use. To justify it to us; as AMD themselves have
               | clearly justified your existence there's no work there!
               | 
               | It's just tough words from a nobody, don't worry you'll
               | be fine!
        
               | latchkey wrote:
               | > You know nobody has trained a thing with your GPU's
               | yet?
               | 
               | https://x.com/zealandic1/status/1877005338324427014
        
           | neuroelectron wrote:
           | Yes ROCm is for the GPU, but the MI300A also includes 4
           | clusters of cpus connected by an infinity fabric. Generally
           | this kind of thing is handled by the OS but there is no OS
           | for this product.
        
             | latchkey wrote:
             | AMD has had APU's for years, the PS5 chip is an APU.
             | 
             | I did a quick google search and found this presentation
             | which details the programming model...
             | 
             | https://nowlab.cse.ohio-
             | state.edu/static/media/workshops/pre...
        
             | alienthrowaway wrote:
             | AMD has been doing IF-connected CCDs/chiplets for a while
             | now - since Zen 1, released in 2017. All the x86 OSes work
             | fine on each iteration.
             | 
             | Application authors who care about wringing out the last
             | drop of performance need to be mindful about how they
             | manage processes and cache lines on this hardware - as they
             | would on any other architecture
        
             | JonChesterfield wrote:
             | What do you mean no OS? You log into whatever Linux
             | distribution someone put on it, that's one of the better
             | magic tricks from having a collection of x64 cores on the
             | same chip. Or I suppose you roll a unikernel style system
             | if you want to.
        
       | mk_stjames wrote:
       | So the 300A is an accelerator coupled with a full 24-core EPYC
       | and 128GB of HBM all on a single chip (or, packaged chiplets,
       | whatever).
       | 
       | Why is it I can't buy a single one of these, on a motherboard, in
       | a workstation format case, to use as an insane workstation?
       | Assuming you could program for the accelerator part, there is an
       | entire world of x86-fixed CAD, engineering, and entertainment
       | industry (rendering, etc) where people want a single, desktop
       | machine with 128GB + of fast ram to number crunch.
       | 
       | There are Blender artists out there that build dual and quad
       | RTX4090 machines with Threadrippers for $20k+ in components all
       | day, because their render jobs pay for it.
       | 
       | There are engineering companies that would not bat an eye at
       | dropping $30k on a workstation if it mean they could spin around
       | 80 gigabyte CATIA models of cars or aircraft loaded in RAM
       | quicker. I know this at least because I sure as hell did with
       | with several HP Z-series machines costing whole-Toyota-Corolla
       | prices over the years...
       | 
       | But these combined APU chips are relegated to these server units.
       | In the end is this a driver problem? Just a software problem? A
       | chicken and egg problem where no one is developing the support
       | because there isn't the hardware on the market, and there isn't
       | the hardware on the market because AMD thinks there is no use
       | case?
       | 
       | Edit: and note my use cases mentioned don't rely on latency,
       | really, like videogamers need to hit framerates. The cache miss
       | latency mentioned in the article doesn't matter as much for these
       | type of compute applications where the main problems are just
       | loading and unloading the massive amount of data. Things like
       | offline renders and post-processing CFD simulations. Not
       | necessarily a video output framerate.
        
         | latchkey wrote:
         | (I run a company that buys MI300x.)
         | 
         | > _Why is it I can 't buy a single one of these, on a
         | motherboard, in a workstation format case, to use as an insane
         | workstation?_
         | 
         | AMD doesn't have the resources to support end users for
         | something like this. They are a public company, look at their
         | spend. They are pouring everything they've got into trying to
         | keep up with the Nvidia release cycle for AI chips.
         | 
         | These chips are cutting edge, they are not perfect. They are
         | still working through the hardware and software issues. It is
         | hard enough to deal with all the public opinion on things as it
         | is. Why would they add another layer of potential abuse?
        
           | AnthonyMouse wrote:
           | The people who buy stuff like that are professionals. They
           | often know something about the tools they're using and if
           | there are any problems, provide bug reports that actually
           | describe what's happening instead of some non-descriptive
           | mush like "I have your GPU and Windows crashes sometimes".
           | That is extremely helpful if you're trying to get rid of
           | those bugs.
           | 
           | This is the same reason software shops have found it useful
           | to support Linux, even if not many people use it. The people
           | who do will make your product suck less, which in turn makes
           | it easier to sell to the mass market, which will get upset
           | and think unfavorably of you if they have the same problem
           | but not be as good at telling you about it.
        
             | Aurornis wrote:
             | > provide bug reports that actually describe what's
             | happening
             | 
             | Doesn't matter if the bug reports are good or bad.
             | Supporting low volume applications is a bad business move
             | when the alternative is 9-figure data center contracts.
             | 
             | The data center business is orders of magnitude larger.
             | Trying to support individual developers would be a huge
             | business mistake when they already can't keep up with data
             | center.
        
               | AnthonyMouse wrote:
               | It's the same hardware running the same software. You
               | want the bug reports so you can fix them and then your
               | data center customers don't encounter them when they're
               | evaluating your product.
               | 
               | What they can keep up with is basically a matter of how
               | much capacity they order from TSMC. If they
               | underestimated demand for some generation, that's the
               | sort of thing you fix with the next contract or you're
               | just throwing money away.
        
             | latchkey wrote:
             | Groq is a good example here:
             | 
             | https://www.eetimes.com/groq-ceo-we-no-longer-sell-
             | hardware/
             | 
             | Our users give them plenty of feedback. They just RMA'd
             | whole bunch of our GPUs over this issue so that they could
             | take them back to the mothership and figure out what's
             | up...
             | 
             | https://github.com/ROCm/ROCm/issues/4021
             | 
             | It takes a lot of coordination, across ourselves (with
             | customers), our DC, AMD and Dell to make that happen.
        
               | AnthonyMouse wrote:
               | It's not that you don't get bug reports from data center
               | customers, it's that data center customers have scale in
               | a bad way. They buy thousands of GPUs, they do whatever
               | they're going to do with them, they have a problem, they
               | report the bug. One bug report across thousands of GPUs,
               | because they're all being used for the same thing by that
               | customer so they only have the problems you have when you
               | try to do that. Another data center buys thousands of
               | GPUs and they're doing something else which is extremely
               | common and well supported, so they don't have any issues
               | and you get _zero_ bug reports from them.
               | 
               | Compare this to, you sell a thousand GPUs to a thousand
               | professionals and 10% of them have some problem, but each
               | a different one. You get 100 bug reports, you fix 100
               | bugs instead of just one, things improve much faster.
        
               | latchkey wrote:
               | We have 136 of these things. Not thousands. AMD is
               | intentionally keeping their number of providers limited
               | [0](bottom of page).
               | 
               | No two providers has the same customers, meaning the
               | workloads vary quite a lot, and a lot of the
               | "professional" developers you're talking about all have
               | jobs that rent this compute.
               | 
               | These GPUs are enterprise, they only come in one form
               | factor. It is a 350lbs box that takes 10kW of power and
               | some pretty serious cooling. It costs as much as an
               | expensive Ferrari.
               | 
               | If you're now also suggesting that AMD also release
               | another product that is easier for developers to get
               | their hands on and deploy, then now you've totally lost
               | me. You're exponentially trying to increase the amount of
               | work and money they spend, for what? Some feedback?
               | 
               | [0] https://www.amd.com/en/products/accelerators/instinct
               | .html
        
               | AnthonyMouse wrote:
               | > We have 136 of these things. Not thousands.
               | 
               | That's a number within an order of magnitude, and you're
               | presumably not the largest provider.
               | 
               | > No two providers has the same customers, meaning the
               | workloads vary quite a lot, and a lot of the
               | "professional" developers you're talking about all have
               | jobs that rent this compute.
               | 
               | If you own something and you've having problems with it,
               | you're more inclined to try to solve them. If you're
               | renting something and you have problems with it, you're
               | more inclined to rent something else instead.
               | 
               | > These GPUs are enterprise, they only come in one form
               | factor. It is a 350lbs box that takes 10kW of power and
               | some pretty serious cooling. It costs as much as an
               | expensive Ferrari.
               | 
               | Making only 4-socket systems was a choice.
               | 
               | You're also acting like multiple SKUs are something
               | weird. Start offering Ryzen APUs with some on-package
               | GDDR or HBM. Make something that fits in the Threadripper
               | socket and uses PCIe power connectors for extra power.
               | People would buy these things.
               | 
               | The point is to create lots of systems in the hands of
               | lots of people that use the same general hardware
               | architecture so that you're improving its software
               | support.
        
               | _zoltan_ wrote:
               | I think you underestimate the people here when you throw
               | around things like "it costs as much as an expensive
               | Ferrari". a lot of us work with systems like these, so we
               | understand why they cost so much and what they can do. On
               | Reddit this works, here, I feel this is pretty
               | condescending.
               | 
               | "Intentionally limiting" is just koolaid. It's ok to
               | drink it, it's your business, but it's koolaid. You think
               | if AWS wanted to deploy a couple hundred thousand of
               | these systems, AMD would be sad? I bet Lisa would be
               | happy.
               | 
               | I tried renting a system, and putting in a credit card is
               | not enough. That's a red flag for me. I don't want to
               | email, chat with sales, etc, just put in a card number.
               | This works for even GH200 systems over at lambda.
               | 
               | As for number of SKUs, for Blackwell there are a lot, if
               | you believe Jensen, and why wouldn't you? He stated at
               | CES that almost every DC they go into is a bit bespoke
               | with modifications.
               | 
               | AMD seems unable to execute on this, which is reflected
               | in its share price.
        
               | latchkey wrote:
               | > I feel this is pretty condescending
               | 
               | Apologies, not my intention.
               | 
               | > I bet Lisa would be happy.
               | 
               | I bet too! I was referring to neoclouds, not tier 1.
               | 
               | > I tried renting a system, and putting in a credit card
               | is not enough.
               | 
               | You truly don't need to talk to anyone, CC and go:
               | https://www.shadeform.ai/
               | 
               | > AMD seems unable to execute on this, which is reflected
               | in its share price.
               | 
               | I agree, they haven't been doing the best job [0]. Let's
               | hope they can show action and turn it around.
               | 
               | [0] https://x.com/HotAisle/status/1880679135875362839
        
               | _zoltan_ wrote:
               | Ok, maybe it works now just by CC. Glad that's sorted.
               | 
               | AMD is tone deaf unfortunately, but I liked your reply on
               | X.
        
         | Aurornis wrote:
         | Data center orders are high volume and allow long lead times.
         | You can collect orders, collect money, and then agree when to
         | deliver huge batches of product.
         | 
         | Selling one off chips isn't attractive at all in this context.
         | Selling a couple parts to the rare Blender artist is nothing
         | relative to the data center buildouts with billion dollar
         | budgets.
         | 
         | Every one-off part you sell takes resources and inventory away
         | from landing those big contracts.
        
         | bluedino wrote:
         | Does AMD build a DGX-like device?
         | 
         | https://www.nvidia.com/en-us/data-center/dgx-platform/?ncid=...
         | 
         | We are trialing some AMD GPUs right now, otherwise we are all
         | NVIDIA.
        
         | JonChesterfield wrote:
         | Supermicro sell them,
         | https://www.supermicro.com/en/accelerators/amd. Other companies
         | probably do too. I'm excited about the ~100W class APUs just
         | announced at CES, hoping for one in a vesa mount format.
        
       | behnamoh wrote:
       | AMD is done, no one uses their GPUs for AI because AMD were too
       | dumb to understand the value of software lock-in like Nvidia did
       | with CUDA.
        
         | guywhocodes wrote:
         | More like the value of drivers that doesn't require one in-
         | house team per customer to "fix" driver crashes in the
         | customers' particular workloads.
        
           | numpy-thagoras wrote:
           | Yeah, the labour involved in running non Nvidia equipment is
           | the elephant in the room.
           | 
           | Nvidia GPU: spin up OS, run your sims or load your LLM,
           | gather results.
           | 
           | AMD GPU: spin up OS, grok driver fixes, try and run your
           | sims, grok more driver fixes, can't even gather results until
           | you can verify software correctness of your fixes. Yeah,
           | sometimes you need someone with specialized knowledge of
           | numerical methods to help tune your fixes.
           | 
           | ... What kind of maddening workflows are these? It's
           | literally negative work: you are busy, you barely get
           | anywhere, and you end up having to do more.
           | 
           | In light of that, the Nvidia tax doesn't look so bad.
        
         | DiabloD3 wrote:
         | Funny you say that, because nobody serious about AI is actually
         | using Nvidia unless they're already locked in with CUDA.
         | 
         | Highest performing inference engines all use Vulkan, and are
         | either faster per dollarwatt on the CDNA3 cards or
         | (surprisingly) the RDNA3 cards, not Lovelace.
        
           | behnamoh wrote:
           | > Funny you say that, because nobody serious about AI is
           | actually using Nvidia unless they're already locked in with
           | CUDA.
           | 
           | Yeah right, so Meta and XAI buying hundreds of Nvidia's
           | H100's was because they were not serious in AI. wtf
        
             | DiabloD3 wrote:
             | Meta has an in-house accelerator that the Triton inference
             | engine supports (which they use almost exclusively for
             | their fake content/fake profiles project). Triton is legacy
             | software and, afaik, does not have a Vulcan backend, so
             | Meta may be locked out of better options until it does.
             | 
             | That doesn't stop Meta's Llama family of models running on
             | anything and everything _outside_ of Meta, though.
             | Llama.cpp works on _everything_ , for example, but Meta
             | doesn't use it.
        
         | buyucu wrote:
         | CUDA lock-in is not what it once was. I do a lot of stable
         | diffusion and I was pleasantly suprised that I could just run
         | the same code on AMD with no changes.
        
       | ChuckMcM wrote:
       | That is quite a thing. I've been out of the 'design loop' for
       | chips like this for a while so I don't know if they still do full
       | chip simulations prior to tapeout but woah trying to simulate
       | that thing would take quite the compute complex in itself. Hat's
       | off to AMD for getting it out the door.
        
       | erulabs wrote:
       | its interesting that two simultaneous and contradictory views are
       | held by AI engineers:
       | 
       | - Software is over
       | 
       | - An impenetrable software moat protects Nvidia's market
       | capitalization
        
       | buyucu wrote:
       | MI300 is an insanely good GPU. There is nothing that Nvidia sells
       | that even comes close. The H100 only has 80GB of memory, whereas
       | MI300 has 192GB. If you are training large models, AMD is the way
       | to go.
        
         | _zoltan_ wrote:
         | H200has more memory and B200 just takes it even more home with
         | cluster wide NVLink.
         | 
         | AMD has zero response to it.
         | 
         | 1.8TB/s interconnect, check.
         | 
         | AWS has this on their new platform as well.
        
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