SPEC - Single-Threaded Performance

Single-thread performance of server CPUs usually isn’t the most important metric for most scale-out workloads, but there are use-cases such as EDA tools which are pretty much single-thread performance bound.

Power envelopes here usually don’t matter, and what is actually the performance factor that comes at play here is simply the boost clocks of the CPUs as well as the IPC improvement, and memory latency of the cores. 

The one hiccup for the Xeon 8380 this generation is the fact that although there’s plenty of IPC gains to be had compared to previous microarchitectures, the new SKU is only boosting up to 3.4GHz, whereas the 8280 was able to boost up to 4GHz, which is a 15% deficit.

SPECint2017 Rate-1 Estimated Scores

Even with the clock frequency disadvantage, thanks to the IPC gains, much improved memory bandwidth, as well as the much larger L3 cache, the new Ice Lake part to most of the time beat the Cascade Lake part, with only a couple of compute-bound core workloads where it falls behind.

SPECfp2017 Rate-1 Estimated Scores

The floating-point figures are more favourable to the ICX architecture due to the stronger memory performance.

SPEC2017 Rate-1 Estimated Total

Overall, the new Xeon 8380 at least manages to post slight single-threaded performance increases this generation, with larger gains in memory-bound workloads. The 8380 is essentially on par with AMD’s 7763, and loses out to the higher frequency optimised parts.

Intel has a few SKUs which offers slightly higher ST boost clocks of up to 3.7GHz – 300Mhz / 8.8% higher than the 8380, however that part is only 8-core and features only 18MB of cache. Other SKUS offer 3.5-3.6GHz boosts, but again less cache. So while the ST figures here could improve a bit on those parts, it’s unlikely to be significant.

SPEC - Multi-Threaded Performance SPEC - Per-Core Performance under Load
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  • mode_13h - Thursday, April 8, 2021 - link

    Please tell me you did this test with an ICC released only a couple years ago, or else I feel embarrassed for you polluting this discussion with such irrelevant facts.
  • Oxford Guy - Sunday, April 11, 2021 - link

    It wasn't that long ago.

    If you want to increase the signal to noise ratio you should post something substantive.

    For instance, if you think think ICC no longer produces faster Blender builds why not post some evidence to that effect?
  • eastcoast_pete - Tuesday, April 6, 2021 - link

    This Xeon generation exists primarily because Intel had to come through and deliver something in 10 nm, after announcing the heck out of it for years. As an actual processor, they are not bad as far as Xeons are concerned, but clearly inferior to AMD's current EPYC line, especially on price/performance. Plus, we and the world know that the real update is around the corner within a year: Sapphire Rapids. That one promises a lot of performance uplift, not the least by having PCI-5 and at least the option of directly linked HBM for RAM. Lastly, if Intel would have managed to make this line compatible with the older socket (it's not), one could at least have used these Ice Lake Xeons to update Cooper Lake systems via a CPU swap. As it stands, I don't quite see the value proposition, unless you're in an Intel shop and need capacity very badly right now.
  • Limadanilo2022 - Tuesday, April 6, 2021 - link

    Agreed. Both Ice Lake and Rocket lake are just placeholders to try to make something before the real improvement comes with Saphire rapids and Alder Make respectively... I'm one that says that AMD really needs the competition right now to not get sloppy and become "2017-2020 Intel". I want to see both competing hard in the next years ahead
  • drothgery - Wednesday, April 7, 2021 - link

    Rocket Lake is a stopgap. Ice Lake (and Ice Lake SP) were just late; they would have been unquestioned market leaders if launched on time and even now mostly just run into problems when the competition is throwing way more cores at the problem.
  • AdrianBc - Wednesday, April 7, 2021 - link

    No, Ice Lake Server cores have a much lower clock frequency and a much smaller L3 cache than Epyc 7xx3, so they are much slower core per core than AMD Milan for any general purpose application, e.g. software compilation.

    The Ice Lake Server cores have a double number of floating-point multipliers that can be used by AVX-512 programs, so they are faster (despite their clock frequency deficit) for the applications that are limited by FP multiplication throughput or that can use other special AVX-512 features, e.g. the instructions useful for machine learning.
  • Oxford Guy - Wednesday, April 7, 2021 - link

    'limited by FP multiplication throughput or that can use other special AVX-512 features, e.g. the instructions useful for machine learning.'

    How do they compare with Power?

    How do they compare with GPUs? (I realize that a GPU is very good at a much more limited palette of work types versus a general-purpose CPU. However... how much overlap there is between a GPU and AVX-512 is something at least non-experts will wonder about.)
  • AdrianBc - Thursday, April 8, 2021 - link

    The best GPUs from NVIDIA and AMD can provide between 3 and 4 times more performance per watt than the best Intel Xeons with AVX-512.

    However most GPUs are usable only in applications where low precision is appropriate, i.e. graphics and machine learning.

    The few GPUs that can be used for applications that need higher precision (e.g. NVIDIA A100 or Radeon Instinct) are extremely expensive, much more than Xeons or Epycs, and individuals or small businesses have very little chances to be able to buy them.
  • mode_13h - Friday, April 9, 2021 - link

    Please re-check the price list. The top-end A100 does sell for a bit more than the $8K list price of the top Xeon and EPYC, however MI100 seems to be pretty close. perf/$ is still wildly in favor of GPUs.

    Unfortunately, if you're only looking at the GPUs' ordinary compute specs, you're missing their real point of differentiation, which is their low-precision tensor performance. That's far beyond what the CPUs can dream of!

    Trust there are good reasons why Intel scrapped Xeon Phi, after flogging it for 2 generations (plus a few prior unreleased iterations), and adopted a pure GPU approach to compute!
  • mode_13h - Thursday, April 8, 2021 - link

    "woulda, coulda, shoulda"

    Ice Lake SP is not even competitive with Rome. So, they missed their market window by quite a lot!

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