Sizing Up Servers: Intel's Skylake-SP Xeon versus AMD's EPYC 7000 - The Server CPU Battle of the Decade?
by Johan De Gelas & Ian Cutress on July 11, 2017 12:15 PM EST- Posted in
- CPUs
- AMD
- Intel
- Xeon
- Enterprise
- Skylake
- Zen
- Naples
- Skylake-SP
- EPYC
Single Threaded Integer Performance: SPEC CPU2006
Even in the server market where high core count CPUs are ruling the roost, high single threaded performance is still very desirable. It makes sure that a certain level of performance is guaranteed in every situation, not just in "throughput situations" of "embarrassingly parallel" software.
SPEC CPU2017 has finally launched, but it did so while our testing was already under way. So SPEC CPU2006 was still our best option to evaluate single threaded performance. Even though SPEC CPU2006 is more HPC and workstation oriented, it contains a good variety of integer workloads.
It is our conviction that we should try to mimic how performance critical software is compiled instead of trying to achieve the highest scores. To that end, we:
- use 64 bit gcc : by far the most used compiler on linux for integer workloads, good all round compiler that does not try to "break" benchmarks (libquantum...) or favor a certain architecture
- use gcc version 5.4: standard compiler with Ubuntu 16.04 LTS. (Note that this is upgraded from 4.8.4 used in earlier articles)
- use -Ofast -fno-strict-aliasing optimization: a good balance between performance and keeping things simple
- added "-std=gnu89" to the portability settings to resolve the issue that some tests will not compile with gcc 5.x
- run one copy of the test
The ultimate objective is to measure performance in non-"aggressively optimized" applications where for some reason – as is frequently the case – a "multi-thread unfriendly" task keeps us waiting.
First the single threaded results. It is important to note that thanks to modern turbo technology, all CPUs will run at higher clock speeds than their base clock speed.
- The Xeon E5-2690 ("Sandy Bridge") is capable of boosting up to 3.8 GHz
- The Xeon E5-2690 v3 ("Haswell") is capable of boosting up to 3.5GHz
- The Xeon E5-2699 v4 ("Broadwell") is capable of boosting up to 3.6 GHz
- The Xeon 8176 ("Skylake-SP") is capable of boosting up to 3.8 GHz
- The EPYC 7601 ("Naples") is capable of boosting up to 3.2 GHz
First we look at the absolute numbers.
| 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 | 35 | 41.6 | 43.4 | 31.1 | 50.1 |
| 401.bzip2 | Compression | 24.5 | 24.0 | 23.9 | 24.0 | 27.1 |
| 403.gcc | Compiling | 33.8 | 35.5 | 23.7 | 35.1 | 24.5 |
| 429.mcf | Vehicle scheduling | 43.5 | 42.1 | 44.6 | 40.1 | 43.3 |
| 445.gobmk | Game AI | 27.9 | 27.8 | 28.7 | 24.3 | 31.0 |
| 456.hmmer | Protein seq. analyses | 26.5 | 28.0 | 32.3 | 27.9 | 35.4 |
| 458.sjeng | Chess | 28.9 | 31.0 | 33.0 | 23.8 | 33.6 |
| 462.libquantum | Quantum sim | 55.5 | 65.0 | 97.3 | 69.2 | 102 |
| 464.h264ref | Video encoding | 50.7 | 53.7 | 58.0 | 50.3 | 67.0 |
| 471.omnetpp | Network sim | 23.3 | 31.3 | 44.5 | 23.0 | 40.8 |
| 473.astar | Pathfinding | 25.3 | 25.1 | 26.1 | 19.5 | 27.4 |
| 483.xalancbmk | XML processing | 41.8 | 46.1 | 64.9 | 35.4 | 67.3 |
As raw SPEC scores can be a bit much to deal with in a dense table, we've also broken out our scores on a percentage basis. Sandy Bridge EP (Xeon E5 v1) is about 5 years old, the servers based upon this CPU are going to get replaced by newer ones. So we've made "Single threaded Sandy Bridge-EP performance" our reference (100%) , and compare the single threaded performance of all other architectures accordingly.
| 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 | 100% | 119% | 124% | 89% | 143% |
| 401.bzip2 | Compression | 100% | 98% | 98% | 98% | 111% |
| 403.gcc | Compiling | 100% | 105% | 70% | 104% | 72% |
| 429.mcf | Vehicle scheduling | 100% | 97% | 103% | 92% | 100% |
| 445.gobmk | Game AI | 100% | 100% | 103% | 87% | 111% |
| 456.hmmer | Protein seq. analyses | 100% | 106% | 122% | 105% | 134% |
| 458.sjeng | Chess | 100% | 107% | 114% | 82% | 116% |
| 462.libquantum | Quantum sim | 100% | 117% | 175% | 125% | 184% |
| 464.h264ref | Video encoding | 100% | 106% | 114% | 99% | 132% |
| 471.omnetpp | Network sim | 100% | 134% | 191% | 99% | 175% |
| 473.astar | Pathfinding | 100% | 99% | 103% | 77% | 108% |
| 483.xalancbmk | XML processing | 100% | 110% | 155% | 85% | 161% |
SPEC CPU2006 analysis is complicated, and with only a few days spend on the EPYC server, we must admit that what follows is mostly educated guessing.
First off, let's gauge the IPC efficiency of the different architectures. Considering that the EPYC core runs at 12-16% lower clockspeeds (3.2 vs 3.6/3.8 GHz), getting 90+% of the performance of the Intel architectures can be considered a "strong" (IPC) showing for the AMD "Zen" architecture.
As for Intel's latest CPU, pay attention to the effect of the much larger L2-cache of the Skylake-SP core (Xeon 8176) compared to the previous generation "Broadwell". Especially perlbench, gobmk, hmmer and h264ref (the instruction part) benefit.
Meanwhile with the new GCC 5.4 compiler, Intel's performance on the "403.gcc benchmark" seems to have regressed their newer rchitectures. While we previously saw the Xeon E5-2699v4 perform at 83-95% of the "Sandy Bridge" Xeon E5-2690, this has further regressed to 70%. The AMD Zen core, on the other hand, does exceptionally well when running GCC. The mix of a high percentage of (easy to predict) branches in the instruction mix, a relatively small footprint, and a heavy reliance on low latency (mostly L1/L2/8 MB L3) seems to work well. The workloads where the impact of branch prediction is higher (somewhat higher percentage of branch misses) - gobmk, sjeng, hmmer - perform quite well on "Zen" too, which has a much lower branch misprediction penalty than AMD's previous generation architecture thanks to the µop cache.
Otherwise the pointer chasing benchmarks – XML procesing and Path finding – which need a large L3-cache, are the worst performing on EPYC.
Also notice the fact that the low IPC omnetpp ("network sim") runs slower on Skylake-SP than on Broadwell, but still much faster than AMD's EPYC. Omnetpp is an application that benefited from the massive 55 MB L3-cache of Broadwell, and that is why performance has declined on Skylake. Of course, this also means that the fractured 8x8 MB L3 of AMD's EPYC processor causes it to perform much slower than the latest Intel server CPUs. In the video encoding benchmark "h264ref" this plays a role too, but that benchmark relies much more on DRAM bandwidth. The fact that the EPYC core has higher DRAM bandwidth available makes sure that the AMD chip does not fall too far behind the latest Intel cores.
All in all, we think we can conclude that the single threaded performance of the "Zen architecture" is excellent, but it somewhat let down by the lower turbo clock and the "smaller" 8x8 MB L3-cache.
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sharath.naik - Wednesday, July 12, 2017 - link
http://www.anandtech.com/show/10158/the-intel-xeon...Here is the link for you a single Xeon E5 v4 22 core does 5.3 (Dual at 5.9)jobs a day compared to dual Epyc 6.3. Ok they are 7% apart for dual socket but only 15% faster for dual epyc compared to single Xeon E5. Big Data does not do well in NUMA set up, same is the case with any regular large data applications. Try running EPYC without splitting spark into multiple processes, you will see how terrible a dual EPYC is going to be (the review mentions it but does not give a graph). Now this is terrible, to use EPYC first you need to change the way you build and run the applications and then expect 7-15% advantage vs a 2000$ CPU. It simple shows that EPYC is only use full for VMs and some synthetic tests. Any applications that deal with data can and should stay away from EPYC
warreo - Friday, July 14, 2017 - link
Why are you comparing Spark 1.5 benchmarks against 2.1.1? Johan pointed out in the article why they are not comparable and why he is using the new 2.1.1 benchmark.The exact Dual Xeon E5 2699 v4 you are referencing that did 5.9 jobs per day in Spark 1.5 only does 4.9 jobs per day on Spark 2.1.1. If we assume a similar % gap between dual and single as it was in Spark 1.5, then a single Xeon E5 2699 v4 would be capable of only 4.4 jobs per day in Spark 2.1.1, which is a 43% difference compared to dual Epycs.
Even leaving that aside, your exact arguments can be applied to the new Xeons as well, which are only 5% faster than the Epycs. Do you think the new Xeons suck as well?
Same thing for splitting Spark into multiple processes and needing to re-write applications -- you also run into the exact same issue with the new Xeons (which Johan also explictly points out).
Based on your arguments, I'm confused why you are taking aim only at Epyc and not the new Xeons. Please let me know if I'm missing something here.
AleXopf - Wednesday, July 12, 2017 - link
Username checks outdeltaFx2 - Wednesday, July 12, 2017 - link
"four 8core desktop dies" Oh, on the contrary. It's really a 4 die MCM server part, and each die is being sold as a desktop part. Nobody puts interconnect (fabric) on a desktop part. MCM is something intel has also done way back in the dual core era, and IBM continues to do. Don't float that canard re. desktop parts, it's just a design choice. AMD isn't trying to beat Intel in every market, just in some, and it does that. It might not win in HPC or big enterprise database (idk), but if you are a public cloud provider in the business of renting 4c8t or 8c16t VMs, AMD has a solid product. Now throw in the 128 PCIe lanes, which intel can't come close to. In fact, a 32c Naples in 1P is something that Intel has nothing to compete against for applications like storage, GPGPU, etc. The question isn't if it's good enough to run Intel out of business in the server space; that's not happening. It didn't when AMD had a superior product in Opteron. The question is, is it good enough for 5-10% market share in 2018-2019?"Intel cores are superior than AMD so a 28 core xeon is equal to ~40 cores if you compare again Ryzen core so this whole 28core vs 32core is a marketing trick". And yet all the numbers presented above point to the opposite. Ryzen != Epyc and i7700K != Syklake EP/SP, if that's where you're getting your numbers from. If not, present data.
Amiga500 - Wednesday, July 12, 2017 - link
No surprise that the Intel employee is descending to lies and deceit to try and plaster over the chasms! They've also reverted to bribing suppliers to offer Ryzen with only crippled memory speeds too (e.g. pcspecialist.co.uk - try and get a Ryzen system with >2133 MHz memory, yet the SKL-X has up top 3600 MHz memory --- the kicker is - they used to offer Ryzen at up to 3000 MHz memory!). It would seem old habits die hard.Hopefully the readers are wise enough to look at the performance data and make their decisions from that.
If OEMs are willing to bend to Intels dirty dollars, I trust customers will eventually choose to take their business elsewhere. We certainly won't be using pcspecialist again in the near future.
Shankar1962 - Wednesday, July 12, 2017 - link
Look at the picture in this article and see what the big players reported when they upgraded to SkylakeDon't hate a company for the sake of argument. The world we live today from a hardware technology standpoint is because of Intel and respect it
https://www.google.com/amp/s/seekingalpha.com/amp/...
Shankar1962 - Wednesday, July 12, 2017 - link
I agree. Intel has been a data center leader and pioneered for decades now. It has proven track record and overall platform stability consistency and strong portfolio and roadmap. With intel transforming to a data company i see that the best is yet to come as it did smart acquisitions and I believe products with IP from those aquired companies are still nnot fully integrated. Everyone loves an underdog and its clear that everyones excited as someone is getting 5% share and Intel won't be sitting....they did it in the past they will do it again:)0ldman79 - Wednesday, July 12, 2017 - link
I find the power consumption info quite interesting, especially considering the TDP ratings for the processors.The platform makes a difference, though I wonder what the actual difference is. Intel and AMD have been rating their TDP differently for years now.
Atom11 - Wednesday, July 12, 2017 - link
After all these tests we still know nothing about AVX512. According to the specs, the floating point should be about 2x faster on CPU with AVX512 in compare to CPU without AVX512. There should be a clear line between Gcc and Icc. Gcc compiler does not support AVX512 anyway and it otherwise also has a relatively limited vectorization support. Not using Icc means, not using the only compiler which actually supports the Intel hardware features. But it yes, it is a difficult comparison, because you need both Instructions and Software which uses those instructions optimized the best way possible and some users simply don't bother about using optimized software. It would be nice to see comparison between: GCC+ AMD and ICC+Intel. So that only compiler is changed, but also the code is written so that it is possible for it to be efficiently vectorized and threaded. What can I get on Intel, if I use best possible software stack and what can I get on AMD? The current article only answers the question: What can i get on AMD and Intel if I dont bother with software stack and optimization.yuhong - Wednesday, July 12, 2017 - link
Inphi has a press release about shipping 1 million DDR3 LR-DIMM buffers six months before the launch of Haswell-E: https://www.inphi.com/media-center/press-room/pres... I wonder how many they shipped total so far (and also Montage).