8 ms·

Do you have actual benchmarks of x86 vs. Power 9 or are you just talking out your ass?

by floren 9y ago

Thaxll 9y ago
With all the stuff running on x86 for the past 30 years + all the perf optimizations in compilers it's not hard to figure. If ARM or Power were faster than x86 we would be using it right now on servers, most of the top500 HPC clusters run on x86_64 ( Intel Xeon ).
- Retra 9y ago
  I don't know why you would think speed is the only thing that determines what is popular.
- shaklee3 9y ago
  The new summit supercomputer uses power9. The reason nobody used it before was there was no server processor available.
  - gnufx 9y ago
    Yes, but most of the compute for Summit and Sierra is in the GPUs. I haven't seen and indication that even those actually have POWER9 yet.
    - shaklee3 9y ago
      They do, and they run many CPU-only applications that will run on the power. See the talks at gtc.
- gnufx 9y ago
  For ARM, specifically, look out Simon Macintosh-Smith's preliminary results for the Isambard system.
berkut 9y ago
For well-optimised floating point calculations, this is generally true (even taking into account the SMT capabilities of Power8). Intel also has 8-wide (and more) SIMD in terms of intrinsics (AVX/AVX512), whilst Power is still limited to 4-wide with AltiVec, although with Power9 VSX should allow wider (I think). Where Power8/9 really shines is memory bandwidth - it's orders of magnitude faster than leading edge Intel stuff currently. But if you're not memory constrained, Intel machines can still have a bit of an edge.
- kev009 9y ago
  AVX512 will severely clock throttle an intel chip. I only want to see real world tests on a workload when comparing the two.
  - berkut 9y ago
    Yes, but even when throttled, it can often be faster than full-clock less wide instructions, if your workload allows for it. So it's sometimes worth it and there is a benefit.
    - flamedoge 9y ago
      It's power throttled by design. I don't think it's heat throttled. I'm sure Intel could push for higher power or optimize power to allow full bandwidth performance, perhaps there isn't a strong demand for sustained, full-width vector execution, yet.
      - nordsieck 9y ago
        > I don't think it's heat throttled. "Processors have two modes of thermal protection, throttling and automatic shutdown. When a core exceeds the set throttle temperature, it will start to reduce power to bring the temperature back below that point." https://www.intel.com/content/www/us/en/support/articles/000005597/processors.html https://www.intel.com/content/www/us/en/support/articles/000...

Do you have actual benchmarks of x86 vs. Power 9 or are you just talking out your ass?

by floren 9y ago

Do you have actual benchmarks of x86 vs. Power 9 or are you just talking out your ass?

With all the stuff running on x86 for the past 30 years + all the perf optimizations in compilers it's not hard to figure. If ARM or Power were faster than x86 we would be using it right now on servers, most of the top500 HPC clusters run on x86_64 ( Intel Xeon ).

Retra 9y ago
I don't know why you would think speed is the only thing that determines what is popular.
shaklee3 9y ago
The new summit supercomputer uses power9. The reason nobody used it before was there was no server processor available.
- gnufx 9y ago
  Yes, but most of the compute for Summit and Sierra is in the GPUs. I haven't seen and indication that even those actually have POWER9 yet.
  - shaklee3 9y ago
    They do, and they run many CPU-only applications that will run on the power. See the talks at gtc.
gnufx 9y ago
For ARM, specifically, look out Simon Macintosh-Smith's preliminary results for the Isambard system.

berkut 9y ago

For well-optimised floating point calculations, this is generally true (even taking into account the SMT capabilities of Power8). Intel also has 8-wide (and more) SIMD in terms of intrinsics (AVX/AVX512), whilst Power is still limited to 4-wide with AltiVec, although with Power9 VSX should allow wider (I think). Where Power8/9 really shines is memory bandwidth - it's orders of magnitude faster than leading edge Intel stuff currently. But if you're not memory constrained, Intel machines can still have a bit of an edge.

kev009 9y ago
AVX512 will severely clock throttle an intel chip. I only want to see real world tests on a workload when comparing the two.
- berkut 9y ago
  Yes, but even when throttled, it can often be faster than full-clock less wide instructions, if your workload allows for it. So it's sometimes worth it and there is a benefit.
  - flamedoge 9y ago
    It's power throttled by design. I don't think it's heat throttled. I'm sure Intel could push for higher power or optimize power to allow full bandwidth performance, perhaps there isn't a strong demand for sustained, full-width vector execution, yet.
    - nordsieck 9y ago
      > I don't think it's heat throttled. "Processors have two modes of thermal protection, throttling and automatic shutdown. When a core exceeds the set throttle temperature, it will start to reduce power to bring the temperature back below that point." https://www.intel.com/content/www/us/en/support/articles/000005597/processors.html https://www.intel.com/content/www/us/en/support/articles/000...