The IBM POWER8 Review: Challenging the Intel Xeon
anandtech.com
anandtech.com
I just wish the hardware was more available. There is precisely one, barely affordable, non-IBM POWER8 system available to buy[2] (if you have $3-4k burning a hole in your pocket). Where are the development boards?
[1] http://research.redhat.com/powerlinux-openpower-development-...
My company runs an IBM POWER7 series system as our ERP/WMS, but that's really only because our vendor sold it as part of a package.
From a user standpoint, POWER architecture just means it will cost me more (on all fronts, from acquisition, to maintenance, to power consumption, etc...). Come upgrade time, it makes it very unlikely I'll be able to unload this system on someone else and recoup anything but a few hundred bucks, sold to someone as a testbench.
When compared to a run-of-the-mill x86 system, POWER doesn't seem to have any real tangible benefits.
Running all cores at full tilt is another story.
On the other hand,IBM have just tried to book three 3-hour long pitching sessions with me so it does not sell itself...
The only niche I can see for a platform that offers maximum performance per-machine at a huge price premium is hard-to-parallelize and legacy applications that need reliable maximum performance in a single box. That's not really that big of a niche these days.
If IBM wants to launch this they're going to have to take a loss to prime the pump: sell the chip at cost or even slightly below cost to get it out there into the market and get people using it. Otherwise it's going nowhere.
That's a shame, they're excellent machines... I guess we'll have to find another sponsor soon.
One big issue to point out:
>Floating Point: NAMD
GCC sucks at automatic hardware vectorization. So does the LLVM. Really the only time you can count on getting automatic hardware vectorization is if you shell out for the ICC AND write your code in Fortran. I'm gonna bet they didn't vectorized a goddamn thing, but we can't inspect anand's binary so we'll never know. The results are still likely correct, but IBM should have lost by a smaller margin.
TL;DR
POWER8 is fun but costs 5k more then Xeon per rack mount and uses about 2x the power usage for 10% less performance on generalized work loads. But can pull off 10-15% more performance on _some specialized_ workloads. So meh?
I agree that gcc sucks for this; we didn't have LLVM last time I was doing this kind of work, so I can't comment on that.
This ends up being -very- fast.
System intrinsics are always your best bet, just really annoying.
#pragma omp simd collapse(N) Goodness grief.
The design language used in those slides has been iteratively refined over decades and exhaustively A/B tested. It has many years of psychometric analysis applied to make it one of the most powerful sales tools in the world.
To win over enterprise PHBs, you need to make them think that you are one of them. That you understand and empathise with them deeply. That you speak their language, and that you are part of their culture.
What better way to do that than to give them a powerpoint presentation that looks just like the ones they give each other. That shows that you are already part of their world, and that you are worthy of the key to the executive washroom.
They are all kind of different.
I used to use Thinkpads and I hated IBM for selling it. But from their point of view it was the absolute right thing to do. High end consumer laptops are dominated by Apple (heck IBM is buying Apple and giving them to all their workers, something like 300K Mac Book Pro's). Everything else is racing to the bottom with thinner and thinner margins. Windows running laptops have to compete with Asus and friends and the money just wasn't there.
Not sure about OS/2 much, don't remember the history. But with POWER, IBM has kind of started to turn around in the last few years.
At some point in the past they have made an explicit choice to not play in the consumer market. Heck, there used to be IBM stores, you'd walk in and buy IBM products like you go to an Apple store now. But they decided they don't want to play in that market (or better or for worse). We'll still see how it ends up working out.
So far it still stays in business after hundreds of years, maybe it just luck or there is something to its business approach. (Fun fact, it used to sell cheese slicers and time tracking devices as well at some point).
Prior to Gerstner, IBM had a variety of esoteric products which were solely designed as loss leaders, never earned a profit, and relied on subsidies by other parts of the company to stay alive. Post 1993, really starting in 1994-1995 these got killed off or sold off, rapidly.
It wasn't enough to break even, one number I recall being thrown around was that we had to get to a 12% Expense-to-Revenue ratio, ignoring SG&A which was a corporate-wide number. Growth products, products in new markets were exempted entirely or given better targets, but old-line products were held to this magical 12% ratio (I was in the mainframe division at the time, which was grotesquely profitable and even today subsidizes much of the rest of IBM).
I was surprised that IBM even had physical stores at some point and today average consumer probably has absolutely no idea what IBM does.
In fact, IBM was really big before computers even arrived. It dominated data processing based on punch cards and was sued for monopoly abuse in the 1930s. It was the original Evil Empire.
Microsoft -- founded in 1975 -- has been spectacularly successful, and IBM's performance has been mediocre for the past 15 years. Even so, Microsoft has only just overtaken IBM in revenues. (Both are now around $93 billion. On any reasonable growth path, IBM would be well over $200 billion.)
See the graph at http://www.zdnet.com/article/tiny-microsoft-overtakes-the-mi...
Indeed, Microsoft would probably be nowhere without IBM. It was IBM that set the PC standard with the IBM Personal Computer in 1981, and Microsoft was lucky to be part of it. In IBM terms, Microsoft stole a small part of IBM's rightful monopoly. IBM's response was to try to kill it with OS/2 EE and the MCA bus in PS/2 computers, as part of SAA.
Arguably they got out of it because there was no such thing as high-end consumer PC hardware, the margins were low, competition fierce, and they didn't want to play in the low-margin discount market.
Arguably the ThinkPad could have been a success as a high end business laptop. I think under Lenovo's stewardship it has languished and become a typical cheap Asian-manufacturer product of 500 SKUs, all slightly different, with quality on a downward curve.
On the other hand the fate of RIM/Blackberry shows there isn't much of a market for a 'business' device that is separate from a high-end 'consumer' device. The latter wins over the former.
The thing is they didn't at all continue on their "business device" strategy, they got suckered into trying to match Apple - they tried going touchscreen crazy and it cost them their core market.
In hindsight, not many people will understand this, but their greatest blunder was trying to charge / keep BES as a revenue product.
They should've given it away far and wide, made it open, encouraged people to customize it.
Imagine if there was a robust, easy to use, free version of BES available? How many business would be using it (>50%)
That would've kept RIM in the game for far longer, but they were short sighted and stupid.
My uninformed take on the issue is that IBM's fabrication technology was never able to deliver on the performance vs. power projections so they traded off power in order to maintain the performance, and that is why POWER takes so much power.
IBM went down the Silicon On Insulator (SOI) path and bet the farm that they could beat Intel's fab technology with that. IBM promised SOI would allow them to make high speed, low power chips. They were unable to deliver on the promise and IBM lost to Intel, along with the rest of the "IBM Alliance" (AMD, Freescale, Chartered Semi, and others).
With respect to the IBM Alliance, it was not kind to any of the members. Many of the members ended up rolled up into Global Foundaries. Global Foundaries was the AMD foundary that was spun out of AMD, Chartered Semi was bought by Global Foundaries, and IBM ended up paying Global Foundaries $1.5 billion (plus took a pretax charge of $4.7 billion) to take their fab plants. Freescale lost the Apple CPU socket because of power and performance problems and has struggled.
Ref:
SOI: https://en.wikipedia.org/wiki/Silicon_on_insulator
Global Foundaries: https://en.wikipedia.org/wiki/GlobalFoundries
Dreams: http://arstechnica.com/gadgets/2007/05/ibm-alliance-will-tak...
Disasters: http://www.bloomberg.com/news/articles/2014-10-19/ibm-agrees...
Also, to be pedantic, POWER is very much not RISC; the only thing it really has in common with RISC is fixed-length instruction encoding (though simpler instruction decoding is an advantage at really low powers).
This doesn't actually answer my question at all, it's just a canned response to something I alluded to in my question (CISC vs. RISC) and a debate which I don't fully understand and would rather avoid. The question was why does POWER consume so much power, not why doesn't POWER being RISC matter? The only reason I compared it to MIPS and ARM was that I thought it was similar to those architectures and they're considered to be low-power.
The impetus is that POWER is actually worse than other architectures, including x86, for unexplained reasons, w.r.t. power consumption.
[edit]
To clarify, the difference between ISAs for power efficiency is negligible at all but the lowest powers, which is what I was trying to say in my original response. The Pentium 4 was far less power efficient than the contemporary G4 PowerPC, as a counterexample. If the power difference between two chips is more than 1 watt per instruction decode unit, you can probably safely assume it's not due to the ISA.
IBM's power consumption is probably mostly because they've never put the processors into energy sensitive applications. More importantly, they are sold because of some benchmarks and extreme reliability.
Note that most ARM processors are two-issue in-order, so RISC is still relevant at the low end. Compare power consumption of ARM vs. equivalent Atom processor. Intel has a process advantage with Atom, but ARM is still lower power.
also as a completely unrelated side-note, the number of processor lines started by Dobberpuhl is crazy: Dec Alpha StrongARM (Became X-Scale), what is now the Broadcom MIPS SoCs. Apple picked him up via an acqui-hire, but he retired the following year.
For example, the 7zip benchmark used in this article is "normalized with results of Intel Core 2 CPU" [1], or the famous Dhrystone integer benchmark's "VAX MIPS" [2].
Still I agree it's weird terminology. It would make more sense to use the true units of the benchmark, or just say "performance relative to reference machine".
Another HNer went into detail as to why the comparison is flawed but basically when you compile with a compiler made by the chip designer, especially for numerical computation, the performance is almost definitely going to slant towards that direction. GCC and Clang have to focus on dozens and dozens of backends. Anandtech has more than enough money to spend 1k for an ICC license.
There are really only two models worth having, at opposite ends of the spectrum: The PowerMac G5 (64-bit, based on POWER4) was the fastest available but they're enormous and power hungry. At the other end, the G4 mini is much smaller and more efficient but 32-bit and not as fast.
The G5 was supported with Fedora until recently but alas support was dropped. Also the newer Power distros are the new ppc64le flavour, which is a slightly different ABI and little endian but the G5 is not alas dual endian so does not support it. But they are cheap and quiet and mine has been running reliably, although I might install FreeBSD on it next as that has ongoing support.
I tried all flavours of PPC linux and none of them worked particularly well. FreeBSD 10.x had the advantage of 64 bit support and the nvidia 6600LE works acceptably with the open source drivers.
I highly recommend FreeBSD 10.x PPC64 to anyone with a G5 PowerMac who wants to run a modern OS.
I still use one to test software because testing on "weird" hardware reveals more bugs.
But obviously not everyone does that, so some of the software in the package manager still has aforementioned bugs.
Since then it has all been about making it look good for enterprise goons. Consolidating and vertical scaling and all that.
And poor buggers that end up with high cpu steal and poor performance because a new box is just unimaginably expensive when you have filled the existing system.