Challenging the Xeon

So what caused us to investigate the IBM POWER8 as a viable alternative to the mass market Xeon E5s and not simply the high-end quad (and higher) socket Xeon E7 parts? A lot. IBM sold its x86 server division to Lenovo. So there is only one true server processor left at IBM: the POWER family. But more importantly, the OpenPOWER fondation has a lot of momentum since its birth in 2013. IBM and the OpenPOWER Foundation Partners like Google, NVIDIA, and Mellanox are all committed to innovating around the POWER processor-based systems from the chip level up through the whole platform. The foundation has delivered some tangible results:

  • Open Firmware which includes both the firmware to boot the hardware (similar to the BIOS) ...
  • ... as OPAL (OpenPOWER Abstraction Layer) to boot and launch a hypervisor kernel.
  • OpenBMC
  • Cheaper and available to third parties (!) POWER8 chips
  • CAPI over PCIe, to make it easier to link the POWER8 to GPUs (and other PCIe cards)
  • And much more third party hardware support (Mellanox IB etc.)
  • A much large software ecosystem (see further)

The impact of opening up firmware under the Apache v2 license and BMC (IBM calls it "field processor") code should not be underestimated. The big hyperscale companies - Google, Amazon, Microsoft, Facebook, Rackspace - want as much control over their software stack as they can.

The resuls are that Google is supporting the efforts and Rackspace has even built their own OpenPOWER server called "Barreleye". While Google has been supportive and showing of proof of concepts, Rackspace is going all the way:

... and aim to put Barreleye in our datacenters for OpenStack services early next year.

The end result is that the complete POWER platform, once only available in expensive high end servers, can now be found inside affordable linux based servers, from IBM (S8xxL) and third parties like Tyan. The opinions of usual pundits range from "too little, too late" to "trouble for Intel". Should you check out a POWER8 based server before you order your next Xeon - Linux server? And why? We started with analyzing the available benchmarks carefully.

A Real Alternative? Reading the Benchmarks
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  • LemmingOverlord - Friday, November 6, 2015 - link

    Mate... Bite your tongue! Johan is THE man when it comes to Datacenter-class hardware. Obviously he doesn't get the same exposure as teh personal technology guys, but he is definitely one of the best reviewers out there (inside and outside AT).
  • joegee - Friday, November 6, 2015 - link

    He's been doing class A work since Ace's Hardware (maybe before, I found him on Ace's though.) He is a cut above the rest.
  • nismotigerwvu - Friday, November 6, 2015 - link

    Johan,

    I think you had a typo on the first sentence of the 3rd paragraph on page 1.

    "After seeing the reader interestin POWER8 in that previous article..."

    Nice read overall and if I hadn't just had my morning cup of coffee I would have missed it too.
  • Ryan Smith - Friday, November 6, 2015 - link

    Good catch. Thanks!
  • Essence_of_War - Friday, November 6, 2015 - link

    That performance per watt, it is REALLY hard to keep up with the Xeons there!
  • III-V - Friday, November 6, 2015 - link

    IBM's L1 data cache has a 3-cycle access time, and is twice as large (64KB) as Intel's, and I think I remember it accounting for something like half the power consumption of the core.
  • Essence_of_War - Friday, November 6, 2015 - link

    Whoa, neat bit of trivia!
  • JohanAnandtech - Saturday, November 7, 2015 - link

    Interesting. Got a link/doc to back that up? I have not found such detailed architectural info.
  • Henriok - Friday, November 6, 2015 - link

    Very nice to see tests of non-x86 hardware. It's interesting too se a test of the S822L when IBM just launched two even more price competitive machines, designed and built by Wistron and Tyan, as pure OpenPOWER machines: the S812LC and S822LC. These can't run AIX, and are substantially cheaper than the IBM designed machines. They might lack some features, but they would probably fit nicely in this test. And they are sporting the single chip 12 core version of the POWER8 processor (with cores disabled).
  • DanNeely - Friday, November 6, 2015 - link

    "The server is powered by two redundant high quality Emerson 1400W PSUs."

    The sticker on the PSU is only 80+ (no color). Unless the hotswap support comes with a substantial penalty (if so why); this design looks to be well behind the state of the art. With data centers often being power/hvac limited these days, using a relatively low efficiency PSU in an otherwise very high end system seems bizarre to me.

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