[HN Gopher] SiFive P550 Core: High-Performance RISC-V Processor
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SiFive P550 Core: High-Performance RISC-V Processor
Author : andrewnc
Score : 145 points
Date : 2021-06-22 14:36 UTC (8 hours ago)
(HTM) web link (www.sifive.com)
(TXT) w3m dump (www.sifive.com)
| zozbot234 wrote:
| The press release mentions that this is a triple-issue OOO
| design. Probably based on BOOM v3/SonicBOOM architecture[0],
| given what we know of previous SiFive designs.
|
| [0] https://github.com/riscv-boom/riscv-boom
| FullyFunctional wrote:
| From the press release:
|
| "Evolved from the previously announced SiFive U84
| microarchitecture,"
|
| The U84 was a from scratch, in-house design.
| ch_123 wrote:
| I hope they release an update of the "Unmatched" motherboard with
| one of these chips. I'm reluctant to spend ~$700 on a platform
| which uses in-order cores which are presumably designed for low-
| power devices.
|
| (Yes, I appreciate I may not be the intended audience for that
| board, but I would still like to build a RISC-V based desktop one
| of these years)
| JensensStapler wrote:
| The P550 core in the title is actually a 3 way issue OOO core
| with near A76 performance, but fair point on the dev boards.
| Hopefully Intel's dev board or some alternative will provide a
| lower cost option.
| marcodiego wrote:
| > said Amber Huffman, Intel Fellow and CTO of IP engineering
| group at Intel.
|
| Hope intel doesn't infect it with IME.
| 1MachineElf wrote:
| Hopefully the recent acquisition rumors don't spell the end of
| this healthy competition between x86 and RISC-V.
|
| I wonder what we'll see as a result of this partnership with
| Intel:
|
| _SiFive also confirmed that the IFC RISC-V application
| development platform will use the Performance P550 core on Intel
| 's 7nm Horse Creek platform._
|
| Link:
| https://www.phoronix.com/scan.php?page=news_item&px=SiFive-P...
| grlass wrote:
| SiFive are definitely amongst the most interesting players in
| RISC-V right now.
|
| Though there other organisations doing things, e.g. the PULP
| Platform: https://news.ycombinator.com/item?id=23768080
|
| I hope that the acquisition doesn't go through, more
| competition would be great, and perhaps within a decade a wider
| commercial RISC-V ecosystem could emerge.
| Koshkin wrote:
| There is no "healthy competition between x86 and RISC-V".
| nine_k wrote:
| Only between RISC-V and ARM?
| dragontamer wrote:
| ARM is a collection of many different cores. So yes, RISC-V
| probably competes well vs ARM-M, but I wouldn't say that
| RISC-V competes against ARM-A (which is starting to become
| big enough to compete against x86).
|
| Just because ARM-M and ARM-A shares an instruction set
| doesn't mean that those chips are anything alike. Heck,
| ARM-M0+ is a completely different chip than ARM-M4.
|
| ARM-R is roughly the target of RISC-V. (Realtime cores).
| monocasa wrote:
| The core in this article wouldn't be a very good ARM-R
| core being OoO. It's about the same niche as an A72
| AFAICT. So RISCV is already nipping at the heels of the
| ARM application core space.
| dragontamer wrote:
| ARM Cortex R8 is out of order.
|
| https://www.arm.com/products/silicon-ip-
| cpu/cortex-r/cortex-...
| monocasa wrote:
| And AFAIK they didn't really get any takers there either
| because it didn't really make sense. I think ARM was
| hoping for a market of large legacy codebases (think cell
| modems) where the heavy hard realtime work had been
| migrated to fixed function IP blocks, DSPs, etc. years
| ago, but the vendor didn't want to spend the time
| migrating their RTOS to ARM-A from ARM-R for the
| intermittent, non realtime, but still compute intensive
| work. You can sort of see how they didn't get any uptake
| with how the marketing changed pretty heavily with the
| R82 towards storage vendors instead of 5G. And RISCV
| doesn't have even the hope of that network effect to bank
| on.
|
| I'd also expect features like per core TCM if this core
| was targeting ARM-R niches to at least break away from
| the non determinism of the memory hierarchy (particularly
| a multi core memory hierarchy!), but I don't see that
| here.
| nickik wrote:
| There are multiple vendors now selling RISC-V products
| that compete with ARM-A as well.
|
| Its not as far alone as the lower end but it defiantly
| happening as well.
| creddit wrote:
| Yeah, I really can't imagine how one would class it as
| healthy let alone even a serious competition. x86 and ARM,
| however, are starting to have a real battle with ARM owning
| mobile, making headwinds into laptops and desktops at Apple
| and multiple vendors producing meaningful server chips.
| JensensStapler wrote:
| Merchant ARM server is mostly dead unfortunately.
| Hyperscalers like AWS are making their own SoCs in house
| however. Amazona acquired Annapurna labs for that purpose.
|
| Personally I see there being more market overlap between
| ARM and the P550 core however. Samsung, Qualcomm, Renesas
| are all planning to bring RISC-V cores to market. With
| performance between A75 and A76, I could see the P550 being
| a pretty major disruptor. We already know some RISC-V chips
| are gaining traction in embedded, IoT, RF, micro-
| controllers, etc. Automotive looks like the next big market
| for RISC-V to me.
| deelowe wrote:
| ARM is making headwinds into server as well now.
| monocasa wrote:
| It's hard to tell apples->apples when you can't buy the
| leading edge ARM servers outright AFAIK. There's a good
| argument that it's in the hyperscalers' best interest to
| discount ARM usage to even below their breakeven to put
| negotiating pressure on their x86 core suppliers as long
| as they balance the costs well enough.
| trevortheblack wrote:
| There was no "healthy competition between msn and google".
| There was no "healthy competition between Blockbuster and
| Netflix". There was no "healthy competition between Barnes &
| Noble and Amazon".
|
| Lack of competition today does not belie there never being
| competition. I would argue that anti-trust should be taken
| against killing/buying your competition when it's still in
| the womb, see Instagram-v-Facebook, WhatsApp-v-Facebook,
| InstagramStories-v-snapchat
| zsmi wrote:
| It's for sure an interesting result but honestly, perf/freq is
| yesterday's spec. What matters in 2021 is perf/W and perf/$ and
| there is no information on either of those metrics.
| LargoLasskhyfv wrote:
| What about perf/degree of safety?
| plantsbeans wrote:
| They mention "performance/area" as being dramatically better
| than Cortex-A75. I'm not familiar with whether area is expected
| to relate to power usage.
| zsmi wrote:
| perf/area comes with a huge number of caveats and it
| basically doesn't mean anything as given.
|
| For example, the exact same verilog, on the same process node
| at the same foundry, can synthesize to very different areas
| depending on the standard library used. They come in a lot of
| varieties with a lot of different trade offs.
|
| For even more detail, the SkyWater130 node, which has been
| popular on HN lately and is public so we can actually post
| links to it, has 6 different mappings that are possible.
| Note, some are called high speed, or high density, etc. You
| get the idea.
|
| https://skywater-
| pdk.readthedocs.io/en/latest/contents/libra...
| wmf wrote:
| SiFive likes to include just enough resources to do well on
| their benchmark du jour (was dhrystone, now SPECint) and
| leave out the rest. So they end up comparing an Arm core with
| NEON against their RISC-V cores with no SIMD/vector support
| for example.
| seg_lol wrote:
| Which is fine because what would normally be handled by the
| SIMD will be custom silicon for most customers and have a
| 4-100x speedup over what SIMD could provide.
| zozbot234 wrote:
| Previous cores had no vector support because the V
| extension that provides for it was nowhere close to being
| standardized. In fact it's yet to be ratified at present,
| so one may want to wait for that before choosing a
| V-capable core for real, actual use.
| chriscappuccio wrote:
| "The SiFive Performance P270 is an 8-stage, dual-issue,
| highly efficient in-order pipeline compatible with the
| RISC-V RV64GCV ISA. With full support for the RISC-V Vector
| Extension v 1.0RC, and combined with SiFive Recode, which
| translates existing SIMD software from popular legacy
| architectures to RISC-V Vector assembly code, the SiFive
| Performance P270 is an ideal replacement for dated SIMD
| architectures."
| meepmorp wrote:
| I'm not even why we're supposed to care about a newly
| launched core beating one that was released in 2017. If
| that's the bar they've set, I'm not exactly wowed.
| NortySpock wrote:
| Gotta start somewhere
| nickik wrote:
| Because the ARM core still has a large market and not every
| application need the maximum performance so having
| competition in that market is not good.
|
| And you are not 'supposed to' care. You can care if you
| want, and ignore it if you want. So I don't really get your
| attitude here.
| ksec wrote:
| >They mention "performance/area" as being dramatically better
| than Cortex-A75.
|
| The P550 pref / area based on Intel 7nm equivalent to TSMC
| 4nm / 3nm that is better than the ARM Cortex A75 released in
| 2017 on TSMC 10nm.
|
| Number using Intel CPU's 7nm, normally Custom Foundry of IFS
| tends to offer lower density but higher flexibility. So this
| is more like a best case scenario.
|
| I am also suspicious of the Intel 7nm number. There are some
| possibility this is actually an Intel 10nm renamed to 7nm for
| custom foundry partners. ( Intel 10nm being equivalent to
| TSMC 7nm )
| JensensStapler wrote:
| No, the area numbers quoted are for TSMC N7. You can look
| up comparable A75 die area numbers for N7 as well. A Cortex
| A76 on TSMC N7 takes up 1.27mm with L2 included. A P550
| takes up 0.38mm.
| truncate wrote:
| How does RISC-V places itself in market? What would be the
| advantage of going RISC over let say ARM (or x86)?
| forgotpwd16 wrote:
| RISC-V is license and royalty-free. This provides more freedom
| to manufacturers to experiment and optimize for specific
| workloads something helped by RISC-V's modular design. Also its
| simpler design makes it attractive to hobbyists as well.
| CameronNemo wrote:
| But in this case (SiFive) the core IP is proprietary.
|
| So what makes this better than an ARM A78 or X1?
| MangoCoffee wrote:
| as backup incase Nvidia manage to buy ARM and squeeze all the
| fabless companies
| CameronNemo wrote:
| And what if Intel buys SiFive and we are back to stunted
| RISC-V cores?
| nickik wrote:
| Go work with System76 and get me a RISC-V RV64GCV Laptop. That
| would be awesome.
| xvilka wrote:
| And a tablet computer.
| kingsuper20 wrote:
| and a little desktop box. Gotta be quicker than a Raspberry
| PI 4 though.
| rwmj wrote:
| AllWinner will likely deliver one of those in the near
| future.
| eric__cartman wrote:
| If they do I hope those chips get better mainline Linux
| kernel support than the ARM based ones. The work the
| Armbian devs are doing is amazing, but they are still
| missing drivers from the manufacturer. Mainly for proper
| graphics and video encoding/decoding. The only operating
| system where this works well is in Android with an archaic
| kernel.
| FullyFunctional wrote:
| The _CPU_ support is already pretty good and for example
| Huawei is pushing important Linux kernel patches.
|
| What you are talking about is drivers for peripherals,
| which is are SoC-level issues, and really up to the
| partners (like Allwinner, SiPeed, etc). So far
| documentation is the most critical part and it's a very
| mixed bag. I think this will be much like the Arm
| experience, albeit everyone is at least using device
| trees these days.
| FullyFunctional wrote:
| I have a C906 and while it's fun, it's very very slow by
| 2021 standards: single core, scalar in-order @ 1.0 GHz with
| no L2$.
|
| The upcoming BeagleV is a lot faster (I have the beta):
| quad core, dual issue in-order @1.5 GHz (TBD) with 2 MiB
| L2.
|
| I'm expecting (guessing) that the triple-issue OoO P550
| would be 5-10X faster at iso-frequency, but if history
| repeats it'll be four+ years before we see it in silicon
| for sale.
| marcodiego wrote:
| Anything RYF certified. Nevermind the manufacturer.
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