[HN Gopher] Video RAM Transplant Doubles RTX3070 Memory to 16GB
___________________________________________________________________
Video RAM Transplant Doubles RTX3070 Memory to 16GB
Author : antman
Score : 130 points
Date : 2021-03-24 07:09 UTC (15 hours ago)
(HTM) web link (hackaday.com)
(TXT) w3m dump (hackaday.com)
| dnautics wrote:
| > So did it make a huge difference? That's difficult to say.
|
| This absolutely would make a difference for many deep learning
| tasks.
| causality0 wrote:
| The stand-out thing to me is that the RTX 3070 only comes with
| 8GB of RAM. The GTX 1070 I bought five years ago with an MSRP
| $100 less than the 3070 (and that I was able to purchase _at
| MSRP_ ) has 8GB of RAM. The GPU I bought five years before that
| only had 1.28GB and before that 256MB. What the hell has the
| industry been doing for the last half decade?
| dnautics wrote:
| I believe the non-RTX (important, confusing with nvidia, as
| usual) 3060 has 12 GB of ram, which makes it a nice buy for
| many ML tasks.
| Sohcahtoa82 wrote:
| non-RTX 3060? I don't think that exists. Got a link to that?
| dnautics wrote:
| whoops. Thanks for correcting me *non-TI. Can't edit parent
| post. And also note some non-TIs have 10GB, not 12 (still
| more than 8GB). Nvidia has successfully confused me =D.
| echlebek wrote:
| The 1070 had GDDR5 RAM and the 3070 has GDDR6X RAM. Instead of
| greater capacity, we get greater bandwidth.
|
| https://graphicscardhub.com/wp-content/uploads/2017/01/gddr6...
| arnaudsm wrote:
| Limiting the RAM so AI researchers buy Quadro/Titan cards.
|
| Just like Canon that downgraded their DSLRs to protect their
| cinema cameras, NVIDIA will loose shares with enthusiasts while
| AMD (which got solid TF/PyTorch support recently) can finally
| catch up.
| rubatuga wrote:
| You will be happy to know that the RTX 3060 has 12GB of VRAM.
| I try BERT-Large training on it here:
|
| https://www.naut.ca/blog/2021/03/16/rtx-3060-vs-jetson-
| agx-f...
| scottlamb wrote:
| > Just like Canon that downgraded their DSLRs to protect
| their cinema cameras, NVIDIA will loose shares with
| enthusiasts while AMD (which got solid TF/PyTorch support
| recently) can finally catch up.
|
| Is this for real? As in: I'm thinking about starting to do
| model training with TensorFlow. I can buy an AMD GPU to use
| for this and not regret it later?
| arnaudsm wrote:
| Here's a tutorial : https://medium.com/analytics-
| vidhya/install-tensorflow-2-for...
|
| I haven't tested myself, but since I have PTSD from Linux
| CUDA installations I'm glad competition is finally here.
| dnautics wrote:
| whether or not the drivers work for quick
| demos/benchmarks is not really what I care about with
| AMD, tbh, their ML pipeline sw QA is bad, historically
| the major problem was long-term stability. Segfaulting 12
| hours into a run is not good for an ML practitioner's
| sanity.
| markus92 wrote:
| Deep learning's going to love this.
| dheera wrote:
| 16GB is pretty meh though. I have a 32GB Titan V from 3 years
| ago which I got for free in a raffle. I'm surprised they're
| still even doing 8GB cards.
| Tenoke wrote:
| Yeah I have the 3070 and I hate that it has the same amount
| of ram as a 1080 from 2016 while costing more than a 1080 did
| at the time.
| SketchySeaBeast wrote:
| That sort of feels like complaining your ferrari has the
| same size gas tank as a Civic. It's not why the car was
| made.
| [deleted]
| dheera wrote:
| I was posting in the context of deep learning
| specifically, per top level comment.
| HappyTypist wrote:
| Well yeah, the comment still applies. GeForce is made for
| gaming, so the bill of materials goes to what improves
| gaming performance.
| SketchySeaBeast wrote:
| It should still do deep learning activities much faster
| than the 1080 though, doesn't it?
| Grazester wrote:
| The size of a car's gas tank has no effect on
| performance. I think the ram size here does, so you
| analogy is not applicable
| herendin2 wrote:
| >The size of a car's gas tank has no effect on
| performance
|
| It has a dramatic effect on performance when you run out
| of gas -- a little bit like the brick wall you hit if you
| run out of memory. The GP'S analogy isn't very accurate,
| but it's not totally wrong
| dheera wrote:
| I guess the analogy works if you could start ripping out
| random components from the car and put them in your gas
| tank and burn them as gas
| HappyTypist wrote:
| For gaming (which these cards are sold and marketed to),
| it doesn't make a difference today.
| ShockedUnicorn wrote:
| It depends on the games you play. I often run out when
| playing VR games, so I have to reduce resolution. Even
| with an 8gb card.
| SketchySeaBeast wrote:
| How do you know that's a memory issue? I'd expect that to
| be less of a concern in VR games and more a requirement
| to render the exact same duplicate resources at slightly
| different perspectives, which should not be memory, but
| pure GPU throughput.
| SketchySeaBeast wrote:
| No, it is - in terms of gaming performance, the thing
| that the 3070 is primarily made for, it's much much
| faster than the 1080 despite having the same amount of
| RAM. It's probably also much faster in Machine Learning
| activities as well.
| coolspot wrote:
| Are you the one of 20 chosen?
|
| https://www.zdnet.com/article/nvidia-reveals-special-32gb-
| ti...
| Scene_Cast2 wrote:
| Yeah. I'm looking to upgrade my 1080, but I'm already running
| into memory limitations. I was actually considering messaging
| the guy and seeing if he can make another one like that. The
| 3080's 10GB isn't very much either, and I really don't want to
| cool 320 watts (too loud).
| HappyTypist wrote:
| You can set a lower limit on the 3090 to be say 250W or even
| 200W. Performance will suffer, but you'll have full access to
| VRAM and it'll be quieter.
| tyingq wrote:
| Looks like the VRAM uses a BGA package with quite a lot of
| contacts. I'm surprised they got 8 of these done well enough, by
| hand with a heat gun, to work.
| varispeed wrote:
| It's fairly easy. Heat the board, drown it in flux, heat the
| part and surface tension will do the rest.
| hinkley wrote:
| I saw someone do a similar act a year or two ago, slightly
| bigger contact pads. I guess if you get the circuit board
| fairly level, and you have dead solid hands, you can get the
| old chip off and leave a little puddle of solder on the
| contacts (which doesn't spread due to surface tension + the
| protective coating on the circuit board?).
|
| If you get the new chip straight (and it looks like he added
| more flux?) then it can bond again. But if you're over
| caffeinated or the chip otherwise twists, or you use the heat
| gun too long, then you have an expensive problem.
| tyingq wrote:
| Gives me anxiety looking at it and the cost/scarcity of an
| RTX3070 :)
|
| I'd want some kind of jig for lowering it.
| tmm wrote:
| Where do you even get video cards right now?
|
| I've become oddly paranoid that mine is going to die and I won't
| be able to find a (reasonably priced) replacement. And two year
| old RX 590s are selling on eBay right now for more than I paid
| for mine. Never imagined that one day video cards would be an
| appreciating asset.
| MR4D wrote:
| I bought my son a used 3060 Ti at the beginning of February
| from Micro Center for $512 + tax. It had been in their display
| machine before that, and never out of the store.
|
| From a timing perspective, I got totally lucky. I happened to
| be there twice in one day, and just got lucky that he had
| dissembled the machine a few minutes before I walked in (he was
| still putting it together with updated parts when I was at the
| counter). Prior to that, I had looked everywhere for weeks (it
| was supposed to be for Christmas!) without any luck.
|
| Patience and luck in my case. And the Micro Center has earned
| me as a loyal customer.
| gorkish wrote:
| *Patience and luck and a willingness to pay way over MSRP for
| a display model
|
| Yeah there are ways to get cards, and I'm not gonna fault
| anyone for interacting with the laws of supply and demand,
| but it seems a bit disingenuous to heap praise and declare
| loyalty to MicroCenter for this. A scalper 5 minutes ahead of
| you would have been given the same "deal" and that card would
| have been on ebay within the hour and mining ETH inside of a
| week, just like the rest of that store's inventory.
| egeozcan wrote:
| Linus from Linus Tech Tips said that he has insider
| information that the problems weren't caused by miners at
| all, it's just that more people are working from home and
| need new hardware:
| https://www.youtube.com/watch?v=3A4yk-P5ukY
| MR4D wrote:
| Great suggestion! I watched it a few hours ago. Fantastic
| episode, and I highly recommend anyone interested in GPUs
| watch it!
| jaynetics wrote:
| Very few people need a GPU for work.
|
| There might be a few, and there might be more gaming, but
| seriously? If I was a miner and could get RTX 3xxx at
| 100-150% MSRP, I'd be buying them non-stop.
|
| A 3070 at MSRP pays for itself via mining in, what, 10
| weeks? And the risk of it being worth less than MSRP any
| time soon seems tiny.
| egeozcan wrote:
| TL;DW: GPUs are competing for chip production capacity of
| 2 producers, who seem to be already in stress because of
| generally increased demand caused by the current
| situation, so they can't handle demand even a tick above
| the previously reserved capacities.
| raarts wrote:
| I'm a teacher streaming from home. There's more of us.
| MR4D wrote:
| > A scalper 5 minutes ahead of you...
|
| I'm not going to argue this point for obvious reasons, but
| short of the work that say, LLTstore is doing, what should
| MicroCenter be doing?
|
| You've got a valid point, which is probably why all of us
| gamers are so pissed off - we're all helpless. It's so
| insane that I'm actually considering trying to find a 3080,
| and then selling his Ti. It would take a bit of work, but
| if I could find one, it would be worth it, and we might
| have an extra year of life out of a more powerful GPU.
| ganoushoreilly wrote:
| I really wish I had a micro center near me. I miss them. I
| also miss the Frys of (late 90's early 2000's).
|
| It's cool though that microcenter is doing the opposite of
| other vendors and doing an in store only thing for cards.
| rchowe wrote:
| I wish MicroCenter would work on their customer experience. I
| go to one in Cambridge, MA to buy IoT supplies and it's never
| organized (despite signs saying "this area stocked by XYZ"),
| popular products are behind the service counter and not even
| in the main area (so you have to ask) and associates rush to
| stick their associate ID barcode on your merchandise and
| usually at check out another associate takes it off and puts
| theirs on. Perverse incentives for sales staff and poor
| customer experience.
|
| But they often do loss-leaders on popular things to get folks
| in the store, so...
| akhilcacharya wrote:
| Wait, has the Cambridge Microcenter had 3080s recently?
| When do they restock?
|
| I've heard of lines in the morning at other Microcenters
| but don't know much about the one next to me.
| robrtsql wrote:
| Buying high-end GPUs? Basically don't bother. You can sign up
| for the Newegg shuffle which happens at least once a week and
| hope you get picked to buy an RTX 3070 but even those are
| pretty expensive. People often brag about how they subscribe to
| notification bots which tell them when Best Buy gets restocked,
| but for every buyer who got lucky, there were hundreds of
| people who dropped what they were doing just to be told that
| the card is now out-of-stock and has been removed from their
| shopping cart.
|
| For lower end GPUs? They're ridiculously expensive, but if a
| card was $100 originally and you have to pay 200% the cost due
| to shortages, it hurts but it's still doable.
|
| Like others have said, it's too bad that you already have a
| rig, because now is a great time to buy prebuilt PCs. The
| '/r/buildapcsales' subreddit usually has people sharing the
| link whenever a decently specced prebuilt PC goes on sale.
| willis936 wrote:
| I had a friend sell me a NIB 3070 this past week for $850. I
| think he bought it for $750. MSRP of the founders edition (FE)
| is $500, but MSRP of all add-in board (AIB) partner cards are
| $600 to $900. Most US retailers are marking up 20+% above MSRP
| when they do have them in stock then scalpers use bots to pick
| them up and resell them on amazon and ebay for 2-3x MSRP.
| Considering I am using my card to mine ethereum (so the card
| pays for itself) and gaming otherwise, I think I did okay for
| myself even though I paid well above what would be considered
| reasonable pricing in a normal year.
|
| Anyway, if you are reading this and want to buy a GPU from a
| retailer you have to attack on all surfaces. Scalpers likely
| write their own bots and spend money to have many accounts
| running at once (to avoid ban limits from IP and account spam
| detection). The higher that GPUs are valued (due to scarcity
| and economic value of mining), the more they will spend and the
| less likely you will ever get a card.
|
| The first thing you need to do is to make accounts on all AIB
| sites (such as EVGA or Zotac) then enter their queue for GPUs.
| They sell some of their cards to people on a FIFO basis and the
| queue is several months long, but this is the most reliable way
| to get a GPU in the next two years.
|
| The next thing you need to do is to join a few discords and
| follow a few twitter accounts (such as stockdrops). Keep your
| bestbuy, newegg, and amazon sign-ins warm on the device you
| will be monitoring (likely your phone).
|
| The final thing you can do is run your own open source bot. I
| only know of fairgame [0]. It's limited to amazon (not a great
| place to look currently) and you can only check one listing
| every 3-5 seconds to avoid a ban. I made an account to do this
| and ran it for a few weeks (with no hits in the MSRP ranges).
| You can check out the cheat sheet (linked in the readme [1]) to
| see a decent list of card listings.
|
| 0. https://github.com/Hari-Nagarajan/fairgame
|
| 1.
| https://docs.google.com/document/d/14kZ0SNC97DFVRStnrdsJ8xbQ...
| yoz-y wrote:
| I was mainly refreshing the pages of as many vendors I've found
| and overpaid. I wonder if Steam, GOG and Epic could somehow
| pool and make a "gamer certificate" to skip ahead of scalpers
| and miners. Nvidia seems to try to brick the drivers of the
| 3060 to discourage mining but I suppose it's not that hard to
| work around.
| PartiallyTyped wrote:
| The Linus Media Group (LinusTechTips etc) is attempting to do
| something just like this.
| yoz-y wrote:
| Interesting, do you have a link or a name of the initiative
| to search for?
| PartiallyTyped wrote:
| I have this, the latest update they gave.
|
| https://www.youtube.com/watch?v=30Uvspk0czw
| yoz-y wrote:
| Thanks! I hope there will be more endeavors like this.
| Cullinet wrote:
| you buy them in workstations through your account manager with
| your friendly tier 1 vendor. ouch I really ought to be doing
| something to provide something beneficial from 3 decades of
| corporate purchasing but just slinging this out there skips the
| pro salesman v pro salesman level of attention required tho it
| isn't rocket science but neither is rocket science... like the
| vram upgrade I genuinely badly want to wave my arms in the air
| shouting "come here I'll fund the smt assembly automation "
| edit the rest is in my profile now since unreadable in line but
| details what I still want to do and will if the opportunity to
| set up shop for people to do like the article with dedicated
| facilities
| pridkett wrote:
| I had to resort to...gasp...ordering a pre-built system. I
| first ordered a Razer Tomahawk - which is a NUC coupled with a
| 3080 Founders Edition. It was about $3300.
|
| The next day I saw I could get an HP Omen which was much more
| maxed out (including physical space) - including a 10 core
| processor, 64GB of RAM, etc and a 3090 with 24GB RAM for about
| the same price.
|
| I feel shameful for having to purchase a pre-built machine, but
| it was the only way I could get one since my contact at NVIDIA
| left the company. On the bright side, if I don't like the
| machine, I can resell just the GPU and recoup almost the entire
| costs.
|
| Unsurprisingly, you can no longer order either machine.
| omgwtfbbq wrote:
| Did the same, was on a pre-order waitlist for a 3080 for
| months before I cracked. But all priced out it was only like
| $500 more for the prebuilt vs buying all the components
| myself. Which considering the markup on 3080s on ebay seems
| like a bargain.
| zepearl wrote:
| > _On the bright side, if I don't like the machine, I can
| resell just the GPU and recoup almost the entire costs._
|
| Damn, you're right - I couldn't believe that but it seems to
| be correct:
|
| - Some random (but available) PC that has an RTX 3080
| included: CHF 2802.- (Switzerland, shop I usually use, all
| their HP Omen with RTX seem to be sold out so I could not use
| that as reference) (
| https://www.digitec.ch/en/s1/product/captiva-g25ag-amd-
| ryzen... )
|
| - RTX 3080 on Amazon.de: EUR 2699.- (
| https://www.amazon.de/Gigabyte-GeForce-Grafikkarte-
| GV-N3080G... )
|
| Incredible times... .
| wccrawford wrote:
| I did the same, but with a 3070. I was going to buy all new
| parts anyhow, and this saved me a lot of hassle, so it was
| worth the extra money IMO.
|
| I still didn't like doing it. It's the first pre-built
| desktop that I've bought ever. And the first one I've owned
| since middle school. But I was sick of waiting and wouldn't
| pay a scalper.
| gnopgnip wrote:
| In the bay area, Central Computers. They have 3070 in stock for
| system builds, and recently they have had 3060 3070 and 3090 in
| stock for standalone purchases. Microcenter and other brick and
| mortar electronics stores across the country are similar.
| a_t48 wrote:
| Caveats: in my experience the Central Computers guys are kind
| of dicks. I've had a couple of bad experiences with them
| before. They also have something like a 10% surcharge over
| "MSRP" for video cards. OTOH - they actually have stock,
| nobody else does. Go for it.
| aaronscott wrote:
| Just seconding this. They have had stock fairly regularly,
| and they have a pretty good notification email for when they
| will have new items available. I purchased a 3090 from them,
| along with a few other parts.
| efrafa wrote:
| I was able to get rtx 3070 last year, but I was refreshing
| eshop whole day.
| Scene_Cast2 wrote:
| So something I've been wondering about for some time. All a GPU
| really is, is a couple of parts. The GPU chip, memory, PCIE,
| voltage regulation, and display outputs.
|
| Now, the voltage regulation is pretty darn standard. You can chop
| up up half of an AMD GPU (the voltagey parts) and Frankenstein
| them to an NVidia GPU and have that still work [0]. The power
| transistors and the controllers (responsible for # of phases) are
| the exact same as in motherboards (they supply the CPU there).
|
| Would it make sense to move the power delivery stuff to a
| separate, longer-lived part? Perhaps as part of the motherboard,
| or maybe have the GPU+memory+display stuff be socketable. Making
| a cheap 400A connector might be somewhat difficult, but not
| impossible.
|
| [0] https://www.youtube.com/watch?v=4frYxrXD5Gc
| https://www.youtube.com/watch?v=ewkVNoMbcCc
| zelon88 wrote:
| I think a better approach for enterprise and high end hardware
| would be socketed capacitor or diode banks. Those are the parts
| that usually deteriorate or fail anyway.
|
| This way you can keep the components close to where they need
| to be and still get that modularity you're looking for.
| bserge wrote:
| Intel tried to do the exact opposite, move the VRM to the
| processor die itself, in Haswell. It did not go well because of
| the extra heat, but those chips make for great overclock
| testbeds haha.
|
| Other than that, why would you move it to a separate part?
| Where? Either you push that extra cost onto the motherboard
| manufacturers or you need a whole new standard and slot for the
| VRM? What's the advantage?
|
| These days, everything is moving towards tighter integration
| (fuck soldered CPUs, RAM and SSDs), so no one is going to do
| that.
| sp332 wrote:
| The advantage is being able to replace the GPU, RAM, etc
| without having to throw away the VRMs.
| zbrozek wrote:
| Those VRMs are not that expensive, and you can't
| realistically move them far away from the load without
| constantly under- or over-voltaging the transistors you're
| trying to power.
|
| Your power company does not deliver 5 volts to your house
| for your phone charger, nor does it transport 240 VAC more
| than a few parcels.
| sokoloff wrote:
| We already have 6 and 8 pin additional connectors on graphics
| cards, so the connector/slot aspect is easily solved.
|
| I think the underlying premise is if you upgrade graphics
| cards more often or otherwise buy 2-4 graphics cards for
| every motherboard you buy that moving the VRM to the
| motherboard (and add costs there), you can still save money
| and reduce waste.
| xxs wrote:
| >We already have 6 and 8 pin additional connectors on
| graphics cards, so the connector/slot aspect is easily
| solved.
|
| Those 8 pins are 12V, not 1V. They are spec'd to carry like
| 12.5A each - make it 15A - bit warmer wires. So around 15W
| per connector at 1V... and the need is over 300W. So there
| you have it 20 8-pin connectors.
|
| There is a reason power lanes of the grid are higher
| voltage - they need a lot less current, so they are
| efficient. Lower voltage should remain on the PCB with
| multiple power planes.
| sokoloff wrote:
| To argue alongside your excellent points: it's not just
| bit warmer wires, but also the underlying voltage drop
| that would be harmful in such a design, especially in the
| context of a 1V DC supply.
| xxs wrote:
| >Would it make sense to move the power delivery stuff to a
| separate, longer-lived part?
|
| Likely no, the voltage regulation is already hard being that
| close to the chips and memory. A modern vrm for rtx 3090 is 16
| phase by 70A stage. The gpus already have multiple power pins
| and with so high amps the losses in the conductor become non-
| trivial, hence voltage regulation is even more difficult.
|
| Moving it farther away would make the regulation extremely
| conservative, overshooting and delivering too high voltage.
|
| Even if all that happens GPUs would still require massive
| amounts of filtering caps.
| baybal2 wrote:
| I believe transformer based "VRMs" (they are actually
| unregulated) like these https://www.techspot.com/images2/news
| /bigimage/2020/05/2020-... is the future as a way more
| practical way to deal with power supply of few hundred Amp
| chips.
|
| 16 phase buck controllers are greatly, greatly impractical,
| and the only reason the industry is stuck with them is that
| nobody was brave enough to do serious research into making
| responsive magnetic based DC-DC, while everybody knew that
| such thing should be possible.
|
| It's interesting curiosity how Taiwanese made it an industry
| trend out of multi-phase bucks because people who were making
| first PCs in Taiwan had rather subpar electronics engineering
| education, or were basically self-taught, and designed
| computer boards by trial end error back in nineties.
| rasz wrote:
| We already had that, and it was terrible. Socket 5 and some 7
| boards shipped with connector for 2.8V VRM. Then then you had
| server boards with elaborate external VRMs, like in the picture
| on the wiki
| https://en.wikipedia.org/wiki/Voltage_regulator_module
| HappyTypist wrote:
| The power delivery part is cheap; it's the chips and memory
| that's expensive.
|
| There's a reason why monitors aren't sold as two parts: the
| display itself and the power circuitry.
| megous wrote:
| Some monitors actually are powered from external adapter. No
| idea how common it is, but one is sitting on my desk.
|
| Interestingly, it's also the one that turns off when there's
| some interference from the lights turning off in the next
| room,...
|
| I guess I'll try re-arranging the wires if that stops the
| pickup of interference.
| dkjaudyeqooe wrote:
| > Interestingly, it's also the one that turns off when
| there's some interference from the lights turning off in
| the next room,...
|
| My Samsung monitor (actually a TV) does this, with any
| spike/dip on the mains line (eg the fridge turning on). I
| assumed this was just poor quality power circuitry.
|
| Is yours a Samsung too by chance?
| xxs wrote:
| >Some monitors actually are powered from external adapter.
| No idea how common it is, but one is sitting on my desk.
|
| Well that's just AC/DC which is similar to the PSU of a
| computer or laptop. The monitor, itself, has voltage
| regulation for much lower volts that the one connected to
| the mains.
| gruez wrote:
| > Some monitors actually are powered from external adapter.
| No idea how common it is, but one is sitting on my desk.
|
| I vaguely remember it was for regulatory reasons. I
| searched around and it looks like it's because with an
| external power supply they only need to certify the brick
| rather than the whole unit https://www.reddit.com/r/sysadmi
| n/comments/24jxfj/anyone_els...
|
| It being thinner is also a bonus.
| jacquesm wrote:
| Yes, that reason is easier UL and CE certification.
| Semaphor wrote:
| Both my monitors have an external brick. Unless that is
| something else?
| xxs wrote:
| This is exactly the same as the laptops have a power brick,
| or desktops have a PSU. It's relatively dumb AC/DC switch
| mode power supply (say ~90-230 to 18VDC) w/o any major care
| about ripple (100mV ripple is amazing already) or even
| exact voltage. The monitors do have more voltage regulation
| inside.
| PragmaticPulp wrote:
| > Would it make sense to move the power delivery stuff to a
| separate, longer-lived part?
|
| That's what your computer's power supply is: A long-lived part
| that delivers bulk 12V power to be regulated down to local
| voltages on the spot.
|
| High performance parts will always need local voltage
| regulation. The VRMs must be physically close to the chip to
| provide a low inductance path to serve fast current transients.
| Moving the VRMs too far away from the chip would compromise the
| power delivery. Running the power through wires or connector
| pins is significantly worse than running through broad power
| planes embedded in the PCB.
|
| At these speeds, designers spend a lot of time simulating and
| analyzing the power delivery network on these PCBs. The power
| regulation and delivery is fine tuned to support the high
| speeds required. You can search for "Power Delivery Network
| Analysis" if you want to learn more.
| dkersten wrote:
| That reminds me of some hardware teardowns (eg of the new
| consoles, latest graphics cards and such) where they show how
| the VRM's are scattered around to balance what they serve as
| equally as possible (to keep heat spread out?) while still
| being as close as possible to what they provide power to. Its
| quite interesting!
| baybal2 wrote:
| A100 uses such "single part" power supply sitting right next
| to the package.
|
| I believe such chips can be easily unsoldered relatively
| easily, and reused.
|
| And by the way, refurbished, and recycles parts, and even
| passives ARE a thing, it's just the part of the industry you
| never see in manufacturing of goods going to first world
| countries, but in China you can buy 2nd hand electronics
| components quite easily.
| MarkSweep wrote:
| As an example of a PC power supply doing things slightly
| differently, the Lenovo P620 has a power supply that connects
| to the motherboard with a slot connector. I heard that it
| only supplies one voltage and the rest of the voltages are
| generated on the board, but I can't find a reference for
| that.
|
| https://www.anandtech.com/show/16482/lenovo-
| thinkstation-p62...
| echlebek wrote:
| This is an awesome comment, thank you! I had long wondered
| myself why GPU power delivery was so complicated.
| uncledave wrote:
| Figures you have to look at to be scared about in this
| space is an RTX 3070 can pull 250 watts and the core is
| 1.2v (I haven't confirmed this) then the card can be
| sucking up an average of 200 amps. Which is a lot. Peak
| currents can be a lot more than that too.
| therein wrote:
| That's a crazy amount of current to pull. I have melted
| wires or even welded things together with a super-
| capacitor setup delivering a similar amount.
| bick_nyers wrote:
| I wonder what cost savings would be passed along doing it this
| way. Also, would PSU be a better (or possible) option? A PSU
| has the ability to outlast a motherboard in the typical
| consumer cycle, as a motherboard will only see 1 or 2 GPUs
| before a system upgrade due to chipset/CPU socket/RAM upgrades
| xxs wrote:
| The proposed idea is not viable for so high currents with so
| little ripple and microseconds transient responses.
| [deleted]
| robotnikman wrote:
| I remember seeing some older video cards, and they actually had
| removable video memory in some slots on the card itself
| formerly_proven wrote:
| Yeah, but the memory in something like a Millenium 2 runs at
| like 1/500th the speed compared to the memory in a modern GPU
| (like the GDDR6X in the RTX 30 series cranking out 21 GBit/s
| per pin). Meanwhile the physics stayed the same.
| Scoundreller wrote:
| I've heard that about SSDs and EEPROMs. They don't require a
| 27V or whatever supply anymore because they'll generate it on-
| die with charge pumps.
|
| But charge pumps are inefficient (like 25% efficient), take up
| a lot of die Space.
|
| It would be better to have a switch mode PS generate the
| voltages required for erasing (effectively required for every
| write). On a USB key, whatever, but on a 24/7 system or laptop,
| it can matter.
|
| Maybe it's a thing now, but it's very recent:
|
| https://e2e.ti.com/blogs_/b/powerhouse/posts/how-to-speed-ss...
| segfaultbuserr wrote:
| > _It would be better to have a switch mode PS generate the
| voltages required for erasing (effectively required for every
| write)._
|
| Interestingly, chips like simple USB and Ethernet controllers
| sometimes do feature an on-die switched-mode DC-DC circuitry
| to simplify the system design. You just connect an inductor
| and a capacitor to the DC-DC pin, and route its output to the
| Vcore input, pretty convenient.
| kardos wrote:
| Do you mean this [1] kind of charge pump? The article
| indicates 90-95% efficient, that's a huge gap from 25%
|
| [1] https://en.wikipedia.org/wiki/Charge_pump
| segfaultbuserr wrote:
| Yes, but the keyword here is "sometimes", charge pumps can
| be efficient only when very specific conditions are met,
| usually low current and power (but there are exceptions),
| efficiency drops sharply as current increases. Putting the
| circuit onto the silicon creates many additional
| limitations.
| buescher wrote:
| I remember dual Pentium Pro motherboards with socketed power
| regulator modules, one for each processor.
| [deleted]
| jacquesm wrote:
| What you will gain in reusability you will more than lose in
| costs for 00 gauge copper wire, space constraints and
| interconnect costs, and likely the transients would still kill
| you.
| osamagirl69 wrote:
| The reason why the VRM is tightly integrated with the asic is
| that there are extremely stringent constraints on the power
| integrity connecting these two parts. To first order, a decent
| GPU draws about 1000 amps of current, so even a single milliohm
| of resistance would absorb the entire voltage supply. Not just
| the ripple tolerance, the entire power rail! This is before we
| even get into the ludicrous requirements on transient behavior,
| inductance, etc, of the connection.
|
| They do make GPUs with a socket for the asic (typically only
| used in test labs) so it is theoretically possible that you
| could for example... buy a 2070 carrier and then get nvidia to
| sell you a 2080 asic to socket into the carrier. But generally
| the technologies used in GPUs change every generation (memory
| technology, number of memory channels, display technologies,
| etc) so you probabably wouldn't be able to keep your carrier
| more than 1 maybe 2 generations tops.
| [deleted]
| SomeHacker44 wrote:
| I think there is a typo in "1000 amps of current."
| [deleted]
| osamagirl69 wrote:
| No, a modern GPU literally draws about 1000 amps of
| current. For example, a non-overclocked 3090 draws about
| 500w under load (some of this goes to memory, but that is
| powered by the motherboard not by the external power
| connector), at a Vcore of roughly 1.1v which gives a bit
| over 450 amps--on average! The peak power consumption (as
| measured on a nanosecond scale being consumed by the asic
| itself) can easily be double the average power consumption
| due to the bursty nature of asic power draw.
| winrid wrote:
| Remember that it's not just one core - that's what makes
| a GPU so powerful. My understanding is it's hundreds or
| thousands of 1.1v cores, which adds up to the 500w.
|
| EDIT - wait, what GPU draws 500w? I can't find one.
| [deleted]
| xxs wrote:
| for desktop GPUs 1000 is bit much, but 600-700A are totally
| doable under LN2
| dogsgobork wrote:
| I think people are conflating watts and amps, watts
| measure power, amps measure flow. Watts = amps * volts.
| High power usage with low voltages results in high
| amperage.
| zokier wrote:
| If Vcore is near 1 volt, then the magnitude difference
| between amps and watts is pretty small for the sort of
| discussion we are h aving
| xxs wrote:
| Even so, in this very case the amps are higher than the
| watts(!) as the voltage is below 1V.
| segfaultbuserr wrote:
| I highly recommend you to read Linear Technology _AN104 - Load
| Transient Response Testing for Voltage Regulators_ [0] to
| understand the staggering challenge in hardware engineering to
| design an acceptable voltage regulator for digital processors.
| Even though it describes 2006 's tech for a simple embedded
| system - it's basically a toy today, but makes a good example.
|
| The problem is transient response. The power consumption of
| digital processors varies wildly. For example, if a processor
| suddenly switches from an idle to active state, a sudden
| increase of current consumption makes the voltage to fall,
| until the regulator is able to react by conducting more power,
| hopefully fast and smooth enough before the processor crashes,
| on the scale of microseconds or even nanoseconds. This is not a
| trivial problem. Inductance is another problem - in any closed
| circuit, every piece of conductor has the tendency to resist
| the change of current, which means even if the regulator itself
| is ideal, if it's too far from the processor, it's physically
| impossible to react fast enough before the output voltage goes
| out of control, thus all ASIC requires local regulation, and
| the end result is extremely sensitive to board layouts and
| components choices.
|
| This note describes how to build a "simulator" to test such
| transient currents and analyzes various circuits for this
| purpose - not very readable and you can just ignore this part.
| Just read page 1, then start reading page 6 ("Capacitor's Role
| in Regulator Response") for some actual tests. Page 8 has a
| practical example: testing a power supply for Intel P30
| Embedded Memory.
|
| > supply tolerances are tight. Figure 26's error budget shows
| only 0.1 V allowable excursion from 1.8 V, including all DC and
| dynamic errors. The LTC1844-1.8 regulator has a 1.75% initial
| tolerance (31.5 mV), leaving only a 68.5 mV dynamic error
| allowance.
|
| 2020 PC hardware is at least two orders of magnitude more
| complex than that. A simple example can be Altera Corporation
| _AN 574: Printed Circuit Board Power Delivery Network Design
| Methodology_ for an FPGA - every single component connected to
| the power supply (and the circuit board itself) must be modeled
| and simulated as a resonant circuit with complicated frequency
| response and impedance characteristics [1].
|
| [0] https://www.analog.com/media/en/technical-
| documentation/appl...
|
| [1]
| https://www.intel.com/content/dam/www/programmable/us/en/pdf...
| caddywompus wrote:
| The last page of the Linear Tech application note is
| certainly not something I expected to see. Glad to see
| they're having some fun
| baybal2 wrote:
| > Making a cheap 400A connector might be somewhat difficult,
| but not impossible.
|
| It will be, I dare you to do.
|
| Inductance will be a problem. GPU makers are already having
| troubles with inductance VRM directly near the chip.
|
| > Now, the voltage regulation is pretty darn standard.
|
| Saying this, take a look on A100
|
| https://www.techspot.com/images2/news/bigimage/2020/05/2020-...
|
| No VRM in a conventional sense. It's a fancy HF DC-DC with
| transformator!
| anthk wrote:
| It happened the same with TV tuner for computers. Standard
| Philips tuner and radio chips, and custom additions plus a PLL
| from the factory.
| baybal2 wrote:
| I'm very surprised that Nvidia chips don't have memory size
| locked in hardware.
| Nextgrid wrote:
| They kind of did - there are resistors on the card's PCB to
| inform the firmware of how much memory is installed and this
| operation modified them to match the new amount of memory
| installed.
|
| But beyond that, what would be the reason of spending effort
| locking this down even more?
| baybal2 wrote:
| Prevent market segmentation bypass.
| Nextgrid wrote:
| The effort & equipment required to perform such an upgrade
| is significant and is very unlikely to be used at scale for
| defeating market segmentation.
| selfhoster11 wrote:
| I can see that happen as an upgrade service on ebay. It
| just needs to be priced competitively.
| gruez wrote:
| I don't see the economics working out. You're going to be
| competing against the 3090, which has 24GB of memory and
| costs 3x as much as a 3070 (MSRP), but also 78% more
| shaders. Just to match the 3090's compute capacity is
| going to cost you $1000 (or $891 if you amortize over
| multiple cards). That leaves you $500 for the memory
| chips, labor, and equipment. According to [1], the memory
| chips cost $12/GB. You won't be able to reuse the
| existing memory chips, so that means you'll need to buy
| 16GB of chips for each of the cards, which works out to
| $384. At this point there's only $116 left, and I doubt
| anyone would go for this considering that the 3090 only
| costs $116 more, but has more memory (24 GB), and has
| full warranty.
|
| [1] https://www.hardwaretimes.com/doubling-graphics-
| memory-will-...
| baybal2 wrote:
| 3090 is largely sold out despite the ludicrous pricetag
| bserge wrote:
| The cost is still going to be high and you risk killing
| your card. Even if someone offered this kind of service,
| it would only be taken by a very small number of
| enthusiasts. So nVidia doesn't care.
| baybal2 wrote:
| Well, there is a precedent of graphic cards with modded
| bios being sold.
| Red_Leaves_Flyy wrote:
| Shhh.
| _verandaguy wrote:
| Economic reasons aside -- there's historical precedent for
| Nvidia creating arbitrary limitations in software (and
| sometimes in dedicated hardware) for their cards.
|
| Famously, many discrete GeForce cards don't play well with
| virtualized OSes, and there have been some hacky ways to
| bypass that. This is done because only Quadro cards are
| blessed by Nvidia to run in "enterprise" environments.
| Besides this soft lock, there's usually no architectural
| limitation preventing GeForce cards from working with
| virtualized OSes if the hypervisor can provide passthrough.
|
| All that to say, it wouldn't be the most shocking news in the
| world if it turned out they prevent this kind of VRAM
| modding.
| babypuncher wrote:
| I'm having trouble imagining a world where the cost of this
| operation is less than the cost difference between a 3070
| and an equivalent 16GB card. Buying the ridiculously
| overpriced 3090 is still going to be cheaper and not come
| with any of the associated risk (invalid warranty,
| potential future driver/bios compatibility problems).
| _verandaguy wrote:
| In this specific case, I think it's more about if you
| _can_ do it rather than if it makes sense. It 's a fun
| challenge, and if you can spare the cash, it does inform
| the community a bit more about how modern Nvidia cards
| react to this kind of mod.
|
| A big fraction of Hackaday's content is this kind of fun
| modding that might not make immediate economic sense.
| bserge wrote:
| Probably because people don't do this at scale. Fermi and
| Kepler also used laser cuts near the die to disable cores, some
| people enabled them with a bit of soldering (not always
| successful because the cores are often actually non-
| functional). Not sure about newer ones.
|
| Maxwell cards could also be upgraded from 4-6GB to 8GB. This
| has actually been a cool mod for a long time, earliest I can
| remember are the ATi Radeon 9x00 and nVidia GeForce 4 Ti cards,
| people used to double the RAM for fun and profit.
| PragmaticPulp wrote:
| It's likely that nVidia planned for more RAM on these cards
| early in the development process. Early rumors pointed to 16GB
| models of the 3070 and 20GB models of the 3080.
|
| Due to chip shortages, most likely, we got the smaller amount
| of RAM on production models. This leads to weird situations
| where the 3060 has more RAM (12GB) than the 3070 (8GB) and 3080
| (10GB). nVidia must use RAM in multiples of the bus width, so
| the only other option was 16GB for the 3070, which is what this
| person enabled by swapping chips.
|
| nVidia doesn't care about modders swapping memory chips because
| it's not a threat to their sales. I say this as someone who has
| all of the hot air rework equipment and experience to do this
| swap: It's not going to become a common mod. It's likely not
| even feasible for someone to offer as a service due to the risk
| involved in shipping expensive GPUs two ways and then reworking
| the PCB with hard to source chips that can't necessarily be
| guaranteed to work at the exact speeds expected by the drivers.
|
| It's also possible that this mod will be rendered useless if a
| future driver update introduces different timing parameters,
| such as when nVidia releases official 16GB 3070 models.
| CivBase wrote:
| > It's not going to become a common mod. It's likely not even
| feasible for someone to offer as a service due to the risk
| involved in shipping expensive GPUs two ways and then
| reworking the PCB with hard to source chips that can't
| necessarily be guaranteed to work at the exact speeds
| expected by the drivers.
|
| That's too bad. I prefer to buy a top-end graphics card once
| every 3 or 4 generations. I was up for a refresh with the
| 20-series, but the value was pretty bad so I waited. Now the
| 30-series looks great except for one glaring issue (aside
| from availability): VRAM capacity. With the imminent release
| of the direct storage API for Windows, I expect the 30-series
| cards will show their age much faster than previous
| generations thanks to their relatively small VRAM capacity
| compared to Radeon and game consoles.
| szczys wrote:
| Doesn't that add manufacturing complexity? If you have multiple
| firmwares it's possible to flash the wrong one at the factory
| leading to a lot of pain if they get out to the market before
| this is discovered (your news 16 GB card is only using 8 GB of
| memory). This current scheme means there is one firmware to
| rule them all and the configuration of the hardware itself acts
| as the selector.
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