Multi-core SPEC CPU2006 - AMD Rome Second Generation EPYC Review: 2x 64-core Benchmarked

Publish date: 2024-08-28

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
SubtestXeon
8176
EPYC
7601
EPYC
7742
EPYC
7742
Zen2
vs
Zen1
EPYC
7742
Vs
Xeon
 
Cores56C64C128C  
Frequency2.8 G2.7G2.5-3.2G2.5-3.2G  
GCC7.47.47.48.37.47.4
400.perlbench1980202046804820+132%+136%
401.bzip21120128032203250+152%+188%
403.gcc1300140035403540+153%+172%
429.mcf92783715401540+84%+66%
445.gobmk1500178041604170+134%+177%
456.hmmer1580170033206480+95%+110%
458.sjeng1570182038603900+112%+146%
462.libquantum870106011801180+11%+36%
464.h264ref2670268064006400+139%+140%
471.omnetpp756705 (*)15201510+116%+101%
473.astar976108015501550+44%+59%
483.xalancbmk1310124028702870+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. 

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