6 ms·

There have been many previous attempts at "throughput computing", meaning many slow cores or threads for server workloads. 3 generations of Niagara (UltraSPARC

by zurn 9y ago

There have been many previous attempts at "throughput computing", meaning many slow cores or threads for server workloads. 3 generations of Niagara (UltraSPARC T1 and descendants), SeaMicro's box full of Atoms, etc. It doesn't mean this is attempt is doomed, but is there compelling answer to "What's different this time?"

dis-sys 9y ago
pushed by a bigger company using a better established architecture and a more reasonable core count.
Xophmeister 9y ago
Intel's Knights Landing / Xeon Phi architecture is a bit like that.
- rbanffy 9y ago
  Eventually we'll face the fact cores won't get any faster and that even phones will have a dozen of them. Porting our code to run well on such machines is a bet people should start making.
  - rjsw 9y ago
    ... or a bet that vendors should start making. Intel could sell bottom bin Xeon Phi chips as development systems. I don't care if half the cores have failed testing and are masked off or it won't run at full speed.
    - rbanffy 9y ago
      I would love if they did that. Developers always have the computers of the future on their desks. If Intel wants Phi to be part of that future, they'd better put them on developers' desks.
  - flyinghamster 9y ago
    Considering that even my far-from-flagship phone has an eight-core processor, I wouldn't be surprised to see a 12-core in the near future.
    - deaddodo 9y ago
      Sure, but that's more like dual-quad (since no one uses Asymmetrical MultiProcessing).
      - rbanffy 9y ago
        Which is also another bet people should start making. Most of the time, my laptop is doing workloads that would leave an Atom bored to death, but when I need it, I sure love those i7 cores. I would gladly sacrifice one i7 core for 4 Atom ones, provided the OS knew what to do with them.
        ryacko 9y ago
        Yeah, it's a latency vs power vs parallelism issue
  - pjmlp 9y ago
    This is one reason why WinRT initially only had async APIs.
- mtgx 9y ago
  Wasn't Phi more of an HPC/machine learning solution, not a server solution? I don't think they target the same kind of applications anyway.
rwmj 9y ago
The difference here is that the individual cores on this are very fast. Unfortunately I cannot publish benchmarks because of NDAs, so you'll have to believe me on this until the hardware is more widely available. https://rwmj.wordpress.com/2017/11/20/make-j46-kernel-builds-on-qualcomm-amberwing/ https://rwmj.wordpress.com/2017/11/20/make-j46-kernel-builds...
- devit 9y ago
  They are decent, but don't seem quite as good as the ones on AMD's (or even more Intel's) processors. Qualcomm Centriq 2434 [https://www.nextplatform.com/2017/11/08/qualcomms-amberwing-arm-server-chip-finally-takes-flight/ https://www.nextplatform.com/2017/11/08/qualcomms-amberwing-...]: - 40 cores (no SMT) - 2.5 GHz peak - 4 uops/instructions per cycle [https://www.qualcomm.com/media/documents/files/qualcomm-centriq-2400-processor.pdf https://www.qualcomm.com/media/documents/files/qualcomm-cent...] - 110 W TDP - $888 - 10 Guops/s/core - 0.011 Guops/s/core/$ - 400 Guops/s - 0.45 Guops/s/$ - 3.63 Guops/s/W AMD Epyc 7401P [https://en.wikipedia.org/wiki/Epyc https://en.wikipedia.org/wiki/Epyc]: - 24 cores (2x SMT) - 2.8 GHz all-core boost - 6 uops per cycle [http://www.agner.org/optimize/microarchitecture.pdf http://www.agner.org/optimize/microarchitecture.pdf] - 170 W TDP - $1075 - 16.8 Guops/s/core - 0.016 Guops/s/core/$ - 403 Guops/s - 0.37 Guops/s/$ - 2.37 Guops/s/W So based on this the AMD processor has 170% the Qualcomm's per-core performance, equal on total throughput, 83% of Qualcomm's total thoughput per $ and 65% of Qualcomm's total throughput per W. Note that the AMD CPU has SMT while the Qualcomm doesn't which improves utilization, and its components are probably faster (due to higher TDP and more experience making CPUs), so it looks like the AMD CPUs are likely to be strictly better in practice except possibly on performance/watt. Also, with AMD/Intel, albeit at much lower performance/$, you can have 32-core instead of 24-core CPUs and there is up to 4/8-way SMP support that Qualcomm doesn't mention.
  - kogepathic 9y ago
    > so it looks like the AMD CPUs are likely to be strictly better in practice except possibly on performance/watt. Cloud scale providers don't care about raw performance (within reason). TCO wins the day, so if Qualcomm CPUs offer higher performance per watt than Intel or AMD, I can definitely see them buying these like hotcakes.
endorphone 9y ago
We can roughly estimate generalized performance per core via their performance per dollar comparisons with Intel. Their 48 core Centriq 2400 is listed at $2000. The 28 core Skylake they compare it to is $10000. They claim 4x better performance per dollar, which puts it at the chip level as 0.8x as fast as the Intel. That would peg every core as 0.5x as fast as the Intel. It won't win a single-thread contest, but that puts it well within the "very fast" category.
wyldfire 9y ago
Re: "What's different this time?" 1. Tier-1 server suppliers like HPE plan to make a Centriq server. For customers to stick their neck out and start porting critical software to a new architecture, they have to believe that there's going to be a refresh next year, and the year after that. Some adventurous customers will be ready to explore this territory but the critical mass won't move until they see momentum shift that way. HPE and Qualcomm each have a popular brand and big budgets that can sustain a slow ramp of a couple generations of these products before they start to see major adoption. 2. What else is different this time is the ever-increasing popularity of: open source software, linux, containerization, python, golang, node/JS, Java, C#, etc. Redhat announced at SC this year that they will offer a supported ARM release. That means that all of the above will Just Work.
jandrese 9y ago
These go way back, the Thinking Machines Corporation was doing stuff like this back in the early 80s. https://en.wikipedia.org/wiki/Connection_Machine https://en.wikipedia.org/wiki/Connection_Machine It didn't pan out that time either, not even on machines with 64k processors.

by zurn 9y ago

dis-sys 9y ago

pushed by a bigger company using a better established architecture and a more reasonable core count.

Xophmeister 9y ago

Intel's Knights Landing / Xeon Phi architecture is a bit like that.

rbanffy 9y ago
Eventually we'll face the fact cores won't get any faster and that even phones will have a dozen of them. Porting our code to run well on such machines is a bet people should start making.
- rjsw 9y ago
  ... or a bet that vendors should start making. Intel could sell bottom bin Xeon Phi chips as development systems. I don't care if half the cores have failed testing and are masked off or it won't run at full speed.
  - rbanffy 9y ago
    I would love if they did that. Developers always have the computers of the future on their desks. If Intel wants Phi to be part of that future, they'd better put them on developers' desks.
- flyinghamster 9y ago
  Considering that even my far-from-flagship phone has an eight-core processor, I wouldn't be surprised to see a 12-core in the near future.
  - deaddodo 9y ago
    Sure, but that's more like dual-quad (since no one uses Asymmetrical MultiProcessing).
    - rbanffy 9y ago
      Which is also another bet people should start making. Most of the time, my laptop is doing workloads that would leave an Atom bored to death, but when I need it, I sure love those i7 cores. I would gladly sacrifice one i7 core for 4 Atom ones, provided the OS knew what to do with them.
      - ryacko 9y ago
        Yeah, it's a latency vs power vs parallelism issue
- pjmlp 9y ago
  This is one reason why WinRT initially only had async APIs.
mtgx 9y ago
Wasn't Phi more of an HPC/machine learning solution, not a server solution? I don't think they target the same kind of applications anyway.

rwmj 9y ago

The difference here is that the individual cores on this are very fast. Unfortunately I cannot publish benchmarks because of NDAs, so you'll have to believe me on this until the hardware is more widely available. https://rwmj.wordpress.com/2017/11/20/make-j46-kernel-builds-on-qualcomm-amberwing/ https://rwmj.wordpress.com/2017/11/20/make-j46-kernel-builds...

devit 9y ago
They are decent, but don't seem quite as good as the ones on AMD's (or even more Intel's) processors. Qualcomm Centriq 2434 [https://www.nextplatform.com/2017/11/08/qualcomms-amberwing-arm-server-chip-finally-takes-flight/ https://www.nextplatform.com/2017/11/08/qualcomms-amberwing-...]: - 40 cores (no SMT) - 2.5 GHz peak - 4 uops/instructions per cycle [https://www.qualcomm.com/media/documents/files/qualcomm-centriq-2400-processor.pdf https://www.qualcomm.com/media/documents/files/qualcomm-cent...] - 110 W TDP - $888 - 10 Guops/s/core - 0.011 Guops/s/core/$ - 400 Guops/s - 0.45 Guops/s/$ - 3.63 Guops/s/W AMD Epyc 7401P [https://en.wikipedia.org/wiki/Epyc https://en.wikipedia.org/wiki/Epyc]: - 24 cores (2x SMT) - 2.8 GHz all-core boost - 6 uops per cycle [http://www.agner.org/optimize/microarchitecture.pdf http://www.agner.org/optimize/microarchitecture.pdf] - 170 W TDP - $1075 - 16.8 Guops/s/core - 0.016 Guops/s/core/$ - 403 Guops/s - 0.37 Guops/s/$ - 2.37 Guops/s/W So based on this the AMD processor has 170% the Qualcomm's per-core performance, equal on total throughput, 83% of Qualcomm's total thoughput per $ and 65% of Qualcomm's total throughput per W. Note that the AMD CPU has SMT while the Qualcomm doesn't which improves utilization, and its components are probably faster (due to higher TDP and more experience making CPUs), so it looks like the AMD CPUs are likely to be strictly better in practice except possibly on performance/watt. Also, with AMD/Intel, albeit at much lower performance/$, you can have 32-core instead of 24-core CPUs and there is up to 4/8-way SMP support that Qualcomm doesn't mention.
- kogepathic 9y ago
  > so it looks like the AMD CPUs are likely to be strictly better in practice except possibly on performance/watt. Cloud scale providers don't care about raw performance (within reason). TCO wins the day, so if Qualcomm CPUs offer higher performance per watt than Intel or AMD, I can definitely see them buying these like hotcakes.

endorphone 9y ago

We can roughly estimate generalized performance per core via their performance per dollar comparisons with Intel. Their 48 core Centriq 2400 is listed at $2000. The 28 core Skylake they compare it to is $10000. They claim 4x better performance per dollar, which puts it at the chip level as 0.8x as fast as the Intel. That would peg every core as 0.5x as fast as the Intel. It won't win a single-thread contest, but that puts it well within the "very fast" category.

wyldfire 9y ago

Re: "What's different this time?" 1. Tier-1 server suppliers like HPE plan to make a Centriq server. For customers to stick their neck out and start porting critical software to a new architecture, they have to believe that there's going to be a refresh next year, and the year after that. Some adventurous customers will be ready to explore this territory but the critical mass won't move until they see momentum shift that way. HPE and Qualcomm each have a popular brand and big budgets that can sustain a slow ramp of a couple generations of these products before they start to see major adoption. 2. What else is different this time is the ever-increasing popularity of: open source software, linux, containerization, python, golang, node/JS, Java, C#, etc. Redhat announced at SC this year that they will offer a supported ARM release. That means that all of the above will Just Work.

jandrese 9y ago

These go way back, the Thinking Machines Corporation was doing stuff like this back in the early 80s. https://en.wikipedia.org/wiki/Connection_Machine https://en.wikipedia.org/wiki/Connection_Machine It didn't pan out that time either, not even on machines with 64k processors.