The IBM POWER8 Review: Challenging the Intel Xeon
by Johan De Gelas on November 6, 2015 8:00 AM EST- Posted in
- IT Computing
- CPUs
- Enterprise
- Enterprise CPUs
- IBM
- POWER
- POWER8
Five years. That is how much time has passed since we have seen an affordable server processor that could keep up with or even beat Intel's best Xeons. These days no less than 95% of the server CPUs shipped are Intel Xeons. A few years ago, it looked like ARM servers were going to shake up the market this year, but to cut a long story short, it looks like the IBM POWER8 chip is probably the only viable alternative for the time being.
That was also noticeable in our Xeon E7 review, which was much more popular than we ever hoped. One of the reasons was the inclusion of a few IBM POWER8 benchmarks. We admit that the article was however incomplete: the POWER8 development machine we tested was a virtual machine with only 1 core, 8 threads and 2 GB of RAM, which is not enough to do any thorough server testing.
After seeing the reader interest in POWER8 in that previous article, we decided to investigate the matter further. To that end we met with Franz Bourlet, an enthusiastic technical sales engineer at IBM and he made sure we got access to an IBM S822L server. Thanks to Franz and the good people of Arrow Enterprise Computing Solutions, Arrow was able to lend us an IBM S822L server for our testing.
A Real Alternative?
Some of you may argue that the POWER based servers have been around for years now. But the slide below illustrates what we typically associated IBM's POWER range with:
Proudly, the IBM sales team states that you can save 1.5 million dollars after you have paid them 2 million dollars for your high-end 780 system. There is definitely a market for such hugely expensive and robust server systems as high end RISC machines are good for about 50,000 clients. But frankly for most of us, those systems are nothing more than an expensive curiosity.
Availability can be handled by software and most of us are looking/forced to reduce our capital expenses rather than increase them. We want fast, "reliable enough" servers at low costs that are easy to service. And that is exactly the reason why the single and dual sockets Xeon servers have been so popular the past decade. Can an IBM POWER server be a real alternative to the typical Xeon E5 server? The short but vague answer: a lot has changed in the past years and months. So yes, maybe.
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Kevin G - Saturday, November 7, 2015 - link
If all you do is just mount the network volume to use the data, then likely nothing at all. While binaries do have to be modified, the file systems themselves are written to store data in a single consistent manner. If you're wondering more if there would be some overhead in translating from LE to BE to work in memory, conceptually the answer is yes but I'd predict it be rather small and dwarfed by the time to transfer data over a network. I'd be curious to see the results.Ultiamtely I'd be more concerned with kernel modules for various peripherals when switching between LE and BE versions. Considering that POWER has been BE for a few generations and you did your initial testing using LE, availability shouldn't be an issue. You've been using the version which should have had the most problems in this regard.
spikebike - Friday, November 6, 2015 - link
So basically power is somewhat competitive with intel's WORST price/perf chips which also happen to have the worst memory bandwidth/CPU. Seems nowhere close for the more reasonable $400-$650 xeons like the D-1520/1540 or the E5-2620 and E5-2630. Sure IBM has better memory bandwidth than the worst intels, but if you want more memory bandwidth per $ or per core then get the E5-2620.JohanAnandtech - Saturday, November 7, 2015 - link
It is definitely not an alternative for applications where performance/watt is important. As you mentioned, Intel offers a much better range of SKUs . But for transactional databases and data mining (traditional or unstructured), I see the POWER8 as very potent challenger. When you are handling a few hundreds of gigabytes of data, you want your memory to be reliable. Intel will then steer you to the E7 range, and that is where the POWER8 can make a difference: filling the niche between E5 and E7.nils_ - Wednesday, November 11, 2015 - link
Especially if you're running software that doesn't easily scale out very well these are very competitive. And nowadays even MySQL will scale-up nicely to many, many cores.Gigaplex - Friday, November 6, 2015 - link
"Less important, but still significant is the fact that IBM uses SAS disks, which increase the cost of the storage system, especially if you want lots of them."The Dell servers I've used had SAS controllers, and every SAS controller I've dealt with supported using SATA drives. I'm pretty sure SATA compatibility is in the SAS specification. In fact, the Dell R730 quoted in this review supports SAS drives. There shouldn't be anything stopping you from using the same drives in both servers.
JohanAnandtech - Saturday, November 7, 2015 - link
You are absolutely right about SATA drives being compatible with a SAS controller. However, afaik IBM gives you only the choice between their own rather expensive SAS drives and SSDs. And maybe I have looked over it, but in general DELL let you only chose between SATA and SSDs. And this has been the trend for a while: SATA if you want to keep costs low, SSDs for everything else.TomWomack - Sunday, November 8, 2015 - link
And mounting a storage server made out of commodity hardware over a couple of lanes of 10Gbit Ethernet if you don't want to pay the exotic-hardware-supplier's markup on disc.Gunbuster - Friday, November 6, 2015 - link
SAP and IBM AIX servers... I guess if you want to blow out your entire IT budget in once easy decision...Jake Hamby - Friday, November 6, 2015 - link
I forgot to mention: VMX is better known as AltiVec (it's also called "Velocity Engine" by Apple). It's a very nice SIMD extension that was supported by Apple's G4 (Motorola/Freescale 7400/7450) and G5 (IBM PPC 970) Macs, as well as the PPC game consoles.It would be interesting to compare the Linux VMX crypto acceleration to code written to use the newer native AES & other instructions. In x86 terms, it'd be like SSE-optimized AES vs. the AES-NI instructions.
Oxford Guy - Saturday, November 7, 2015 - link
I had a dual 450 MHz G4 system and AltiVec was quite amazing in iTunes when doing encoding. Between the second processor and the AltiVec putting things into ALAC was very fast (in comparison with other machines at the time like the G3 and the AMD machines I had).