SMT Integer Performance With SPEC CPU2006

Next, to test the performance impact of simultaneous multithreading (SMT) on a single core, we test with two threads on the same core. This way we can evaluate how well the core handles SMT. 

Subtest Application type Xeon E5-2690 @ 3.8 Xeon E5-2690 v3 @ 3.5 Xeon E5-2699 v4 @ 3.6 EPYC 7601 @3.2 Xeon 8176 @ 3.8
400.perlbench Spam filter 39.8 43.9 47.2 40.6 55.2
401.bzip2 Compression 32.6 32.3 32.8 33.9 34.8
403.gcc Compiling 40.7 43.8 32.5 41.6 32.1
429.mcf Vehicle scheduling 44.7 51.3 55.8 44.2 56.6
445.gobmk Game AI 36.6 35.9 38.1 36.4 39.4
456.hmmer Protein seq. analyses 32.5 34.1 40.9 34.9 44.3
458.sjeng Chess 36.4 36.9 39.5 36 41.9
462.libquantum Quantum sim 75 73.4 89 89.2 91.7
464.h264ref Video encoding 52.4 58.2 58.5 56.1 75.3
471.omnetpp Network sim 25.4 30.4 48.5 26.6 42.1
473.astar Pathfinding 31.4 33.6 36.6 29 37.5
483.xalancbmk XML processing 43.7 53.7 78.2 37.8 78

Now on a percentage basis versus the single-threaded results, so that we can see how much performance we gained from enabling SMT:

Subtest Application type Xeon E5-2699 v4 @ 3.6 EPYC 7601 @3.2 Xeon 8176 @ 3.8
400.perlbench Spam filter 109% 131% 110%
401.bzip2 Compression 137% 141% 128%
403.gcc Compiling 137% 119% 131%
429.mcf Vehicle scheduling 125% 110% 131%
445.gobmk Game AI 125% 150% 127%
456.hmmer Protein seq. analyses 127% 125% 125%
458.sjeng Chess 120% 151% 125%
462.libquantum Quantum sim 91% 129% 90%
464.h264ref Video encoding 101% 112% 112%
471.omnetpp Network sim 109% 116% 103%
473.astar Pathfinding 140% 149% 137%
483.xalancbmk XML processing 120% 107% 116%

On average, both Xeons pick up about 20% due to SMT (Hyperthreading). The EPYC 7601 improved by even more: it gets a 28% boost on average. There are many possible explanations for this, but two are the most likely. In the situation where AMD's single threaded IPC is very low because it is waiting on the high latency of a further away L3-cache (>8 MB), a second thread makes sure that the CPU resources can be put to better use (like compression, the network sim). Secondly, we saw that AMD core is capable of extracting more memory bandwidth in lightly threaded scenarios. This might help in the benchmarks that stress the DRAM (like video encoding, quantum sim). 

Nevertheless, kudos to the AMD engineers. Their first SMT implementation is very well done and offers a tangible throughput increase. 

Single Threaded Integer Performance: SPEC CPU2006 Multi-core SPEC CPU2006
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  • Kaotika - Tuesday, July 11, 2017 - link

    http://www.anandtech.com/show/11464/intel-announce...
    This one remains wrong though
  • Ian Cutress - Tuesday, July 11, 2017 - link

    Always reference the newest piece, especially the main review.
    Or we'd spend half of our time going back and updating old pieces and reviews with new data.
  • scottb9239 - Tuesday, July 11, 2017 - link

    On the POV-RAY benchmark, shouldn't that read as almost 16% faster than the dual 2699 v4 and 32% faster than the dual 8176?
  • scienceomatica - Tuesday, July 11, 2017 - link

    I think that a fair game would be to compare the top offer of one and the other manufacturer, in other words, the Xeon 8180 should be included in the benchmark regardless of the aspect of the price. Then the difference would be quite in favor of the Intel processor, although it has few cores less.
  • Tamz_msc - Tuesday, July 11, 2017 - link

    Will we get to see more FP HPC-oriented workloads like SPECfp2006 or even 2017 being discussed in a future article?
  • lefty2 - Tuesday, July 11, 2017 - link

    I can summarize this article: "$8719 chip beaten by $4200 chip in everything except database and Appache spark."
    Well done Intel, another Walletripper!
  • Shankar1962 - Wednesday, July 12, 2017 - link

    Then why did google att aws etc upgraded to skylake. They could have saved billions of dollars.
  • Shankar1962 - Wednesday, July 12, 2017 - link

    Look at what big players upgrading to skylake reported
    These are real workloads
    No one cares about labs
    These numbers decide who wins and who loses
    No wonder AMD sells at $4200

    https://www.google.com/amp/s/seekingalpha.com/amp/...
  • nitrobg - Tuesday, July 11, 2017 - link

    Pricing on page 10 should reflect that the 2P EPYC prices are for 2 processors, not per CPU. The price of Xeons is per CPU.
  • coder543 - Tuesday, July 11, 2017 - link

    That doesn't seem true. The prices they currently have seem to be correct. Got a source?

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