Multi-core SPEC CPU2006

For the record, we do not believe that the SPEC CPU "Rate" metric has much value for estimating server CPU performance. Most applications do not run lots of completely separate processes in parallel; there is at least some interaction between the threads. But since the benchmark below caused so much discussion, we wanted to satisfy the curiosity of our readers. 

 

2P SPEC CPU2006 Estimates
Subtest Xeon
8176
EPYC
7601
EPYC
7742
EPYC
7742
Zen2
vs
Zen1
EPYC
7742
Vs
Xeon
 
Cores 56C 64C 128C    
Frequency 2.8 G 2.7G 2.5-3.2G 2.5-3.2G    
GCC 7.4 7.4 7.4 8.3 7.4 7.4
400.perlbench 1980 2020 4680 4820 +132% +136%
401.bzip2 1120 1280 3220 3250 +152% +188%
403.gcc 1300 1400 3540 3540 +153% +172%
429.mcf 927 837 1540 1540 +84% +66%
445.gobmk 1500 1780 4160 4170 +134% +177%
456.hmmer 1580 1700 3320 6480 +95% +110%
458.sjeng 1570 1820 3860 3900 +112% +146%
462.libquantum 870 1060 1180 1180 +11% +36%
464.h264ref 2670 2680 6400 6400 +139% +140%
471.omnetpp 756 705 (*) 1520 1510 +116% +101%
473.astar 976 1080 1550 1550 +44% +59%
483.xalancbmk 1310 1240 2870 2870 +131% +119%

We repeat: the SPECint rate test is likely unrealistic. If you start up 112 to 256 instances, you create a massive bandwidth bottleneck, no synchronization is going on and there is a consistent CPU load of 100%, all of which is very unrealistic in most integer applications. 

The SPECint rate estimate results emphasizes all the strengths of the new EPYC CPU: more cores, much higher bandwidth. And at the time it ignores one of smaller disadvantages: higher intercore latency. So this is really the ideal case for the EPYC processors. 

Nevertheless, even if we take into account that AMD has an 45% memory bandwidth advantage and that Intel latest chip (8280) offers about 7 to 8% better performance, this is amazing. The SPECint rate numbers of the EPYC 7742 are - on average - simply twice as high as those of the best available socketed Intel Xeons.

Interestingly, we saw that most rate benchmarks ran at  P1 clock or the highest p-state minus one. For example, this is what we saw when running libquantum:

While some benchmarks like h264ref were running at lower clocks. 

The current server does not allow us to do accurate power measuring but if the AMD EPYC 7742 can stay within the 225W TDP while running integer workloads at all cores at 3.2 GHz, that would be pretty amazing. Long story short: the new EPYC 7742 seems to be able to sustain higher clocks than comparable Intel models while running integer workloads on all cores. 

 

Single-Thread SPEC CPU2006 Legacy: 7-zip
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  • Kevin G - Wednesday, August 7, 2019 - link

    Clock speeds. AMD is being very aggressive on clocks here but the Ryzen 3000 series were still higher. I would expect new Threadripper chips to clock closer to their Ryzen 3000 cousins.

    AMD *might* differentiate Threadripper by cache amounts. While the CPU cores work, they may end up binning Threadripper based upon the amount of cache that wouldn't pass memory tests.

    Last thing would be price. The low end Epyc chips are not that expensive but suffer from low cores/low clocks. Threadripper can offer more for those prices.
  • quorm - Wednesday, August 7, 2019 - link

    Here's hoping we see a 16 core threadripper with a 4ghz base clock.
  • azfacea - Wednesday, August 7, 2019 - link

    half memory channels. half pcie lanes. also i think with epyc AMD spends more on support and system development. i can see 48c 64c threadripper coming 30-40% lower and not affecting epyc
  • twtech - Wednesday, August 7, 2019 - link

    If they gimp the memory access again, it mostly defeats the purpose of TR as a workstation chip. You'd want an Epyc anyway.
  • quorm - Wednesday, August 7, 2019 - link

    Well, on the plus side, the i/o die should solve the asymmetric memory access problem.
  • ikjadoon - Wednesday, August 7, 2019 - link

    Stunning.
  • aryonoco - Wednesday, August 7, 2019 - link

    Between 50% to 100% higher performance while costing between 40% to 50% less. Stunning!

    I remember the sad days of Opteron in 2012 and 2013. If you'd told me that by the end of the decade AMD would be in this position, I'd have wanted to know what you're on.

    Everyone at AMD deserves a massive cheer, from the technical and engineering team all the way to Lisa Su, who is redefining what "execution" means.

    Also thanks for the testing Johan, I can imagine testing this server at home with Europe's recent heatwave would have not been fun. Good to see you writing frequently for AT again, and looking forward to more of your real world benchmarks.
  • twtech - Wednesday, August 7, 2019 - link

    It's as much about Intel having dropped the ball over the past few years as it is about AMD's execution.

    According to Intel's old roadmaps, they ought to be transitioning past 10nm on to 7nm by now, and AMD's recent releases in that environment would have seemed far less impressive.
  • deltaFx2 - Wednesday, August 7, 2019 - link

    Yeah, except I don't remember anyone saying Intel was going great guns because AMD dropped the ball in the bulldozer era. AMD had great bulldozer roadmaps too, it didn't matter much. If bulldozer had met its design targets maybe Nehalem would not be as impressive... See, nobody ever says that. It's almost like if AMD is doing well, it's not because they did a good job but intel screwed up.

    Roadmaps are cheap. Anyone can cobble together a powerpoint slide.
  • Lord of the Bored - Thursday, August 8, 2019 - link

    Well, it is a little of both on both sides.
    Intel's been doing really well in part because AMD bet hard on Bulldozer and it didn't pay out.

    Similarly, when AMD's made really good processors but Intel was on their game, it didn't much matter. The Athlon and the P2/3 traded blows in the Megahertz wars, but in the end AMD couldn't actually break Intel because Intel made crooked business deals*backspace* because AMD was great, but not actually BETTER.

    The Athlon 64 was legendary because AMD was at the top of their game and Intel was riding THEIR Bulldozer into the ground at the same time. If the Pentium Mobile hadn't existed, thus delaying a Netburst replacement, things would be very different right now.

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