Comparing With the Other ARMs

We did not have access to any recent Cortex-A57 or X-Gene platform to run the full SPEC CPU2006 suite. But we can still combine our previous findings with those that have been published on the 7-cpu.com. The first X-Gene 1 result is our own measurement, the second one is the best we could find.

SKU Clock Baseline Xeon D Compress Baseline Xeon D Decompress
Atom C2720 2.4 1687 2114
X-Gene 1 (AT bench) 2.4 1580 1864
X-Gene 1 (best) 2.4 1770 1980
Cortex-A57 1.9 1500 2330
ThunderX 2.0 1547 2042
Xeon D1557 1.5-2.1 3079 2320
Xeon E5-2640 v4 2.4-2.6 3755 2943
Xeon E5-2690 v3 2.6-3.5 4599 3811

Let's translate this to percentages, where we compare the Thunder-X performance to the Xeon D and the Cortex-A57, two architectures it must try to beat. The first one is to open a broader market, the second one to justify the development of a homegrown ARMv8 microarchitecture.

SKU Clock Baseline Xeon D Compress Baseline Xeon D Decompress Baseline A57 Compress Baseline A57 Decompress
Atom C2720 2.4 55% 91% 112% 91%
X-Gene (AT bench) 2.4 51% 80% 105% 80%
X-Gene (best) 2.4 57% 85% 118% 85%
Cortex-A57 1.9 49% 100% 100% 100%
ThunderX 2.0 50% 88% 103% 88%
Xeon D1557 2.1 100% 100% 205% 100%
Xeon E5-2640 v4 2.4 122% 127% 250% 126%
Xeon E5-2690 v3 3.5 149% 164% 307% 164%

First of all, these benchmarks should be placed in perspective: they tend to have a different profile than most server applications. For example compression relies a lot on memory latency and TLB efficiency. Decompression relies on integer instructions (shift, multiply). Since this test has unpredictable branches, the ThunderX has an advantage.

The ThunderX at 2 GHz performs more or less like an A57 core at the same speed. Considering that AMD only got eight A57 cores inside a power envelope of 32W using similar process technology, you could imagine that a A57 chip would be able to fit 32 cores at the most in a 120W TDP envelope. So Cavium did quite well fitting about 50% more cores inside the same power envelope using an old 28 nm high-k metal gate process.

Nevertheless, a 120W Xeon E5 offers about 2.5-3 times higher compression performance. The gap is indeed much smaller in decompression, where the wide Broadwell core is only 13% (!) faster than the narrow ThunderX core (compare the Xeon D-1557 with the ThunderX).

Multi-Threaded Integer Performance: SPEC CPU2006 Compression & Decompression
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  • silverblue - Thursday, June 16, 2016 - link

    I think AMD themselves admitted that the Opteron X1100 was for testing the waters, with K12 being the first proper solution, but that was delayed to get Zen out of the door. I imagine that both products will be on sale concurrently at some point, but even with AMD's desktop-first approach for Zen, it will probably still come to the server market before K12 (both are due 2017).
  • junky77 - Thursday, June 16, 2016 - link

    still, quite strange, no? AMD is in the server business for years. I'm not talking about their ARM solution only, but their other solutions seem to be less interesting..
  • silverblue - Thursday, June 16, 2016 - link

    I am looking forward to both Zen and K12; there's very little chance that AMD will fail with both.
  • name99 - Wednesday, June 15, 2016 - link

    " It is the first time the Xeon D gets beaten by an ARM v8 SoC..."

    The Apple A9X in the 12" iPad Pro delivers 40GB/s on Stream...
    (That's the Stream built into Geekbench. Conceivably it's slightly different from what's being measured here, but it delivers around 25GB/s for standard desktop/laptop Intel CPUs, and for the A9 and the 9" iPad's A9X, so it seems in the same sort of ballpark.)
  • aryonoco - Thursday, June 16, 2016 - link

    Fantastic article as always Johan. Thank you so much for your very informative articles. I can only imagine how much time and effort writing this article took. It is very much appreciated.

    The first good showing by an ARMv8 server. Nearly 5 years later than expected, but they are getting there. This thing was still produced on 28 HKMG. Give it one more year, a jump to 14nm, and a more mature software ecosystem, and I think the Xeons might finally have some competition on their hands.
  • JohanAnandtech - Thursday, June 16, 2016 - link

    Thank you, and indeed it was probably the most time consuming review ... since Calxeda. :-)
    Yes, there is potential.
  • iwod - Thursday, June 16, 2016 - link

    Even if the ThunderX is half the price of equivalent Xeon, I would still buy Intel Xeon instead. This isn't Smartphone market. In Server, The cost memory and Storage, Networking etc adds up. Not only does it uses a lot more power in Idle, the total TCO AND Pref / Watts still flavours Intel.

    There is also the switching cost of Software involved.
    And those who say Single Core / Thread Performance dont matter have absolutely no idea what they are talking about.

    As far as I can tell, Xeon-D offers a very decent value proposition for even the ARM SoC minded vendors. This will likely continue to be the case as we move to 10nm. I just dont see how ARM is going to get their 20% market share by 2020 as they described in their Shareholder meetings.
  • rahvin - Thursday, June 16, 2016 - link

    If you have to switch software on your severs because you switch architecture you are doing something wrong and are far too dependent on proprietary products. I'm being a bit facetious here but the only reason architecture should limit you is you are using Microsoft products or are in a highly specialized computing field. Linux should dominate your general servers.
  • kgardas - Friday, June 17, 2016 - link

    Even if you are on Linux, still stack support is best on i386/amd64. Look at IBM how it throws a lot of money to get somewhere with POWER8. ARM can't do that, so it's more on vendors to do that and they are doing it a little bit more slowly. Anyway, even AArch64 will mature in LLVM/GCC tool chain, GNU libC, musl libC, linux kernel etc but it'll take some time...
  • tuxRoller - Thursday, June 16, 2016 - link

    Aarch64 has very limited conditional execution support.
    http://infocenter.arm.com/help/index.jsp?topic=/co...

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