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
Energy and Pricing
Unfortunately, accurately and fairly comparing energy consumption at the system level between the S822L and other systems wasn't something we were able to do, as there were quite a few differences in the hardware configuration. For example, the IBM S822L had two SAS controllers and we had no idea how power hungry that chip under the copper heatsink was. Still there is no doubt that the dual CPU system is by far the most important power consumer when the server system is under load. In case of the IBM system, the Centaur chips will take their fair share too, but those chips are not optional. So we can only get a very rough idea how the power consumption compares.
| Xeon E5 299 v3/POWER8 Comparison (System) | ||
| Feature | 2x Xeon E5-2699v3 | 2x IBM POWER8 3.4 10c IBM S822L |
| Idle | 110-120W | 360-380W |
|
Running NAMD (FP) |
540-560W |
700-740W |
| Running 7-zip (Integer) |
300-350W |
780-800W |
The Haswell core was engineered for mobile use, and there is no denying that Intel's engineers are masters at saving power at low load.
The mightly POWER8 is cooled by a huge heatsink
IBM's POWER8 has pretty advanced power management, as besides p-states, power gating cores and the associated L3-cache should be possible. However, it seems that these features were not enabled out-of-the box for some reason as idle power was quite high. To be fair, we spent much more time on getting our software ported and tuned than on finding the optimal power settings. In the limited time we had with the machine, producing some decent benchmarking numbers was our top priority.
Also, the Centaur chips consume about 16W per chip (Typical, 20W TDP) and as we had 8 of them inside our S822L, those chips could easily be responsible for consuming around 100W.
Interestingly, the IBM POWER8 consumes more energy processing integers than floating point numbers. Which is the exact opposite of the Xeon, which consumes vastly more when crunching AVX/FP code.
Pricing
Though the cost of buying a system might be only "a drop in the bucket" in the total TCO picture in traditional IT departements running expensive ERP applications, it is an important factor for almost everybody else who buys Xeon systems. It is important to note that the list prices of IBM on their website are too high. It is a bad habit of a typical tier-one OEM.
Thankfully we managed to get some "real street prices", which are between 30% (one server) and 50% (many) lower. To that end we compared the price of the S822L with a discounted DELL R730 system. The list below is not complete, as we only show the cost of the most important components. The idea is to focus on the total system price and show which components contribute the most to the total system cost.
| Xeon E7v3/POWER8 Price Comparison | ||||
| Feature | Dell R730 | IBM S822L | ||
| Type | Price | Type | Price | |
| Chassis | R730 | N/A | S822L | N/A |
| Processor | 2x E5-2697 | $5000 | 2x POWER8 3.42 | $3000 |
| RAM | 8x 16GB DDR4 DIMM |
$2150 | 8x 16 GB CDIMM (DDR3) | $8000 |
| PSU | 2x 1100W | $500 | 2x 1400W | $1000 |
| Disks | SATA or SSD | Starting at $200 |
SAS HD/SSD | +/- $450 |
| Total system price (approx.) | $10k | $15k | ||
With more or less comparable specs, the S822L was about 50% more expensive. However, it was almost impossible to make an apples-to-apples comparison. The biggest "price issue" are the CDIMMs, which are almost 4 times as expensive as "normal" RDIMMs. CDIMMs offer more as they include an L4-cache and some extra features (such as a redundant memory chip for each 9 chips). For most typical current Xeon E5 customers, the cost issue will be important. For a few, the extra redundancy and higher bandwidth will be interesting. 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.
This cost issue will be much less important on most third party POWER8 systems. Tyan's "Habanero" system for example integrates the Centaur chips on the motherboard, making the motherboard more expensive but you can use standard registered DDR3L RDIMMs, which are much cheaper. Meanwhile the POWER8 processor tends to be very reasonably priced, at around $1500. That is what Dell would charge for an Intel Xeon E5-2670 (12 cores at 2.3-2.6 GHz, 120W). So while Intel's Xeon are much more power efficient than the POWER8 chips, the latter tends to be quite a bit cheaper.
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hissatsu - Friday, November 6, 2015 - link
You might want to look more closely. Thought it's a bit blurry, I'm almost certain that's the 80+ Platinum logo, which has no color.DanNeely - Friday, November 6, 2015 - link
That's possible; it looks like there's something at the bottom of the logo. Google image search shows 80+ platinum as a lighter silver/gray than 80+ silver; white is only the original standard.Shezal - Friday, November 6, 2015 - link
Just look up the part number. It's a Platinum :)The12pAc - Thursday, November 19, 2015 - link
I have a S814, it's Platinum.johnnycanadian - Friday, November 6, 2015 - link
Oh yum! THIS is what I still love about AT: non-mainstream previews / reviews. REALLY looking forward to more like this. I only wish SGI still built workstation-level machines. :-(mapesdhs - Tuesday, November 10, 2015 - link
Indeed, but it'd need a hefty change in direction at SGI to get back into workstations again, so very unlikely for the forseeable future. They certainly have the required base tech (NUMALink6, MPI offload, etc.), namely lots of sockets/cores/RAM coupled with GPUs for really heavy tasks (big data, GIS, medical, etc.), ie. a theoretical scalable, shared-memory workstation. But the market isn't interested in advanced performance solutions like this atm, and the margin on standard 2/4-socket systems isn't worthwhile, it'd be much cheaper to buy a generic Dell or HP (plus, it's only above this no. of sockets that their own unique tech comes into play). Pity, as the equivalent of a UV 30/300 workstation would be sweet (if expensive), though for virtually all of the tasks discussed in this article, shared memory tech isn't relevant anyway. The notion of connectable, scalable, shared memory workstations based on NV gfx, PCIe and newer multi-core MIPS CPUs was apparently brought up at SGI way back before the Rackable merger, but didn't go anywhere (not viable given the financial situation at the time). It's a neat concept, eg. imagine being able to connect two or more separate ordinary 2/4-socket XEON workstations together (each fitted with, say, a couple of M6000s) to form a single combined system with one OS instance and resources pool, allowing users to combine & split setups as required to match workloads, but it's a notion whose time has not yet come.
Of course, what's missing entirely is the notion of advanced but costly custom gfx, but again there's no market for that atm either, at least not publicly. Maybe behind the scenes NV makes custom stuff the way SGI used to for relevant customers (DoD, Lockheed, etc.), but SGI's products always had some kind of commercially available equivalent from which the custom builds were derived (IRx gfx), whereas atm there's no such thing as a Quadro with 30000 cores and 100GB RAM that costs $50K and slides into more than one PCIe slot which anyone can buy if they have the moolah. :D
Most of all though, even if the demand existed and the tech could be built, it'd never work unless SGI stopped using its pricing-is-secret reseller sales model. They should have adopted a direct sales setup long ago, order on the site, pricing configurator, etc., but that never happened, even though the lack of such an option killed a lot of sales. Less of an issue with the sort of products they sell atm, but a better sales model would be essential if they were to ever try to sell workstations again, and that'd need a huge PR/sales management clearout to be viable.
Pity IBM couldn't pay NV to make custom gfx, that'd be interesting, but then IBM quit the workstation market aswell.
Ian.
mostlyharmless - Friday, November 6, 2015 - link
"There is definitely a market for such hugely expensive and robust server systems as high end RISC machines are good for about 50.000 servers. "Rounding error?
DanNeely - Friday, November 6, 2015 - link
50k clients would be my guess.FunBunny2 - Friday, November 6, 2015 - link
(dot) versus (comma) most likely. Euro centric versus 'Murcan centric.DanNeely - Friday, November 6, 2015 - link
If that was the case, a plain 50 would be much more appropriate.