The Intel Xeon E7-8800 v3 Review: The POWER8 Killer?
by Johan De Gelas on May 8, 2015 8:00 AM EST- Posted in
- CPUs
- IT Computing
- Intel
- Xeon
- Haswell
- Enterprise
- server
- Enterprise CPUs
- POWER
- POWER8
POWER8 Servers: The Reality Check
As we've just seen, the specs of the POWER8 as announced at launch are very impressive. But what about the in the real world? The top models (10-12 at 4 GHz+, 2TB per socket) are still limited to the extremely expensive E870/E880, which typically costs around 3 times as much (or more) as a comparable Xeon E7 system. But there is light at the end of the tunnel: "PowerLinux" quad socket systems are more expensive than comparable x86 systems, but only by 10 to 30%.
The real competition for x86 must probably come from the third parties of the OpenPower Fondation. IBM sells them POWER8 chips at much more reasonable prices ($2k - $3k), so it is possible to build a reasonably priced POWER8 system. The POWER8 chips sold to third parties are somewhat "lighter" versions, but that is more an advantage than you would think. For example, by keeping the clockspeed a bit lower, the power consumption is lower (190W TDP). These chips also have only 4 (instead of 8) memory buffer chips, which "limits" them to 1 TB of memory, but again this saves quite a bit of power, between 50W and 80W. In other words, the POWER8 chips available to third parties are much more reasonable and even more competitive than the power gobbling, ultra expensive behemoths that got all the attention at launch.
Tyan already has an one socket server and several Taiwanese (Wistron) and Chinese vendors are developing 2 socket systems. Quad socket models are not yet on the horizon as far as we know, but is probably going to change soon.
POWER8 vs. Xeon E5 v3: SPECing It Out
Unfortunately we did not have access to a full blown POWER8 system at this time. But as our loyal readers know, we do not limit our server testing to the x86 world (see here and here) . So until a POWER8 system arrives, we'll have to check out the available industry standard benchmarks. To that end we looked up the SPEC CPU2006 numbers for a single socket CPU.
The 12 cores inside the POWER8 - the single socket chips found in the more reasonable priced servers - perform very well. The integer performance is only a few percentages lower than the Intel chip and POWER8's floating point performance is well ahead of the Xeon.
Overall the POWER8 is quite capable of keeping up with the Xeon E5-2699v3. And don't let the "2.3 GHz" official clockspeed fool you into thinking that the Xeons are clocked unnecessarily low, either: in SPECint, the XEON is running at 2.8 GHz most of the time.
Ultimately, the POWER8 is able to offer slightly higher raw performance than the Intel CPUs, however it just won't be able to do so at the same performance/watt. Meanwhile the reasonable pricing of the POWER8 chips should result in third party servers that are strongly competitive with the Xeon on a performance-per-dollar basis. Reasonably priced, well performing dual and quad socket Linux on Power servers should be possible very soon.
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DanNeely - Friday, May 8, 2015 - link
Intel's 94% market share is still only ~184k systems. That's tiny compared to the mainstream x86 market; and doesn't give a lot of (budgetary) room to make radical changes to CPU vs just scaling shared designs to a huger layout.theeldest - Friday, May 8, 2015 - link
184k for 4S systems. The number of 2S systems *greatly* outnumbers the 184k.Samus - Sunday, May 10, 2015 - link
by 100 orders of magnitude, easily.2S systems are everywhere these days, I picked up a Lenovo 2S Xeon system for $600 NEW (driveless, 4GB RAM) from CDW.
4S, on the other hand, is considerably more rare and starts at many thousands, even with 1 CPU included.
erple2 - Sunday, May 10, 2015 - link
Well, maybe 2 orders of magnitude. 100 orders of magnitude would imply, based on the 184k 4S systems, more 2S systems than atoms in the universe. Ok, I made that up, I don't know how many atoms are in the universe, but 10^100 is a really big number. Well, 10^105, if we assume 184k 4S systems.I think you meant 2 orders of magnitude.
mapesdhs - Sunday, May 10, 2015 - link
Yeah, that made me smile too, but we know what he meant. ;)evolucion8 - Monday, May 11, 2015 - link
That would be right if Intel cores are wide enough which aren't compared to IBM. For example, according to this review, enabling two way SMT boosted the performace to 45% and adding two more threads added 30% more performance. On the other hand, enabling two way SMT on the latest i7 architecture can only go up to 30% on the best case scenario.chris471 - Friday, May 8, 2015 - link
Great article, and I'm looking forward to see more Power systems.I would have loved to see additional benchmarks with gcc flags -march=native -Ofast. Should not change stream triad results, but I think 7zip might profit more on Power than on Xeon. Most software is not affected by the implied -ffast-math.
close - Friday, May 8, 2015 - link
It reminds me of the time when Apple gave up on PowerPC in mobiles because the new G5s were absolute power guzzlers and made space heaters jealous. And then gave up completely and switched to Intel because the 2 dual core PowerPC 970MP CPUs at 2.5GHz managed to pull 250W of power and needed liquid cooling to be manageable.IBM is learning nothing from past mistakes. They couldn't adapt to what the market wanted and the more nimble competition was delivering 25-30 years ago when fighting Microsoft, it already lost business to Intel (which is actually only nimble by comparison), and it's still doing business and building hardware like we're back in the '70s mainframe age.
name99 - Friday, May 8, 2015 - link
You are assuming that the markets IBM sells into care about the things you appear to care about (in particular CPU performance per watt). This is a VERY dubious assumption.The HPC users MAY care (but I'd need to see evidence of that). For the business users, the cost of the software running on these systems dwarfs the lifetime cost of their electricity.
SuperVeloce - Saturday, May 9, 2015 - link
They surely care. Why wouldn't they. A whole server rack or many of them in fact do use quite a bit of power. And cooling the server room is very expensive.