That's two new servers in as many days during a pretty high profile time for it. They won't be getting 50% marketshare anytime soon, but Power8 seems to be a good design. NVLink is a nice advantage too; I hope we see a bigger IBM presence in the future.
POWER8 is not a good design, but you have been tricked by IBM marketing to believe so. For instance, POWER8 in general is slower than the fastest x86 cpu. For instance, in SPEC2006, the E5-2699v3 reaches 715 whereas POWER8 reaches 642. Of course, the SPARC M7 is the record holder with 1200 SPECint2006. Here are all the numbers: https://blogs.oracle.com/BestPerf/entry/201510_spe...
In general the SPARC M7 is 2-3x faster than POWER8 or x86, all the way up to 11x faster. In the link above are 25ish different benchmarks such as databases, SPECjbb2005, Hadoop Terasort, Neural networks, etc etc. Just read the benchmarks.
I dont really understand why anybody would want to sell POWER8 servers, as they are slower than x86 and more expensive? -POWER6 was several times faster than x86 and costed 10x more -POWER7 was 10-20% faster than x86 and costed 3x more -POWER8 is slower than x86 and still more expensive? This is bad news for POWER, as IBM only does high margin business and walks away from low margin business. And POWER9 must be cheaper than x86 because it will be slower. Nobody will buy POWER anymore.
Oh BTW, IBM has officially said that AIX will be killed off. AIX runs on POWER, so without AIX, why sell slow POWER servers? http://www.cnet.com/news/ibm-linux-is-the-logical-... "...Asked whether IBM's eventual goal is to replace AIX with Linux, Mills responded, "It's fairly obvious we're fine with that idea...It's the logical successor."
You're comparing Intel's just released to IBM's two years old. And you're assuming that the performance characteristics of IBM's target audience (on the one hand, very large data HPC, on the other hand very large I-footprint business code) match SPEC2006. These are both dubious assumptions.
POWER8+ will probably be released soon, with enough tweaks (frequency and cache, probably) to match x86; while POWER9 will have 24 cores.
Meanwhile Google continues to look into POWER as a possible CPU for some of its servers (perhaps in the context of driving nV GPUs for AI neural networks). Intel kinda sorta has a vague plan to counter things like nVLink through either using Xeon Phi or one day shipping a Xeon with an on-board FPGA, but it's not clear that either of these solutions is absolutely superior to IBM's solutions.
How is Power8+ going to get frequency & cache improvements when the process isn't changing (its still at 22nm)? While Power8 was "announced" in August 2013, real 12-core Power8 chips delivered in systems didn’t get announced till April 2015, almost 2 years later. If anything, I believe IBM will just trickle down the higher GHZ Power8's @ the higher GHzes down to the lower end systems, where currently the weaker Power8's are today. Maybe even installing 12-core Power8 onto DCM's to double-up the core count per system.
"...POWER8+ will probably be released soon, with enough tweaks (frequency and cache, probably) to match x86; while POWER9 will have 24 cores...."
Well, if POWER8+ can match x86 it is good for IBM. But I doubt that. Intel is not resting, and when POWER8+ arrives, there will be new Xeons, even faster. And cheaper. So, why would anyone buy POWER8+? Oh, if you want to loose money big time.
POWER8+ (apparently now renamed "POWER8 with NVLink") will arrive this year. This year's Xeon's have already arrived. So we will probably have parity of the newest Xeons (the largest E7 v4's) with the POWER8's of the next few months.
Next year POWER9 will be on 14nm FF (compare with 22nm today). So huge process improvement, obviously being used to double density, and likely either increase per-core resources or bump up frequency slightly. Meanwhile next year's Skylake Xeons will be on 14nm FF (just like this year's Broadwell Xeons) so no process improvement, and just a few percentage points micro-architecture performance improvement. Which means that for 2017 POWER9 is likely to be way ahead of Skylake Xeon.
At some point, of course, Intel will eventually move to 10 nm. But the Kaby Lake delays show that their process improvement has slowed down. They might have two years or so of 10nm before GF get there --- but they will likely use those two years shipping first mobile then desktop, so the Xeon's at 10nm will arrive maybe only a few months before 2020's POWER10.
A second interesting aspect, as yet not clear, is whether POWER will have the chance to explode like ARM has done by having Chinese [or even Japanese] third parties design their own SoCs around a basic POWER core. This seems to be what IBM wants to happen, but I don't think the actual plan specifics are public knowledge. Obviously there are a different set of diificulties in translating the design for a core (or whatever IBM sells) into a full SoC from doing the same with an ARM core targeting mobile. But I could imagine that the Chinese government would be willing to subsidize at least one company to do the necessary research. And it's even possible that Fujitsu might decide this is a more useful path going forward than continuing with SPARC.
Of course these are simply theories, but I don't think they're utterly crazy. If IBM could reinvent (part of) itself as something like an ARM for HPC, that might be good enough to keep POWER viable for quite a few more years.
You conveniently forget to mention that you're comparing a 32 core (M7) and 18 core (Intel) CPU to a 10 core Power8 CPU. Also, the Power8 CPU is very close to the Intel chip in SPECfp. Its per core performance is the highest of the three under SPEC_rate.
And for Database workloads like OLTP, running the open source HammerDB benchmark test, based on TPC-C, shows SPARC M7, with its 32-cores, outperforms 4 x Power8's totaling 24-cores by 37%, therefore showcasing higher performance/core. SPARC M7 also surpassed a dual-Xeon E5-2699 v3 with 36-cores total by a whopping 38%, showcasing a 55% performance/core advantage. https://blogs.oracle.com/BestPerf/entry/20160317_s... Theres several other real-world benchmarks showcasing SPARC M7 better performance/core. And even Power9 won't be 24-cores till atleast 2018!
@milli What has the number of cores to do anything? I am talking about which CPU is fastest, not which core is fastest. And when we compare cpu to cpu, Intel x86 is faster than POWER8.
So my point still holds; I dont understand why anyone would buy a slow POWER8 when they can buy a faster x86? And cheaper. x86 gives more performance for a cheaper sum. There is absolutely no reason anyone would want to migrate from fast cheap x86, to slow and expensive POWER8.
Eh? The POWER8 is besting Intel in both performance per core and performance per clock. That is incredibly impressive. The examples in the link you cite as fast require far more cores to reach those performance levels.
Wow, you never miss an opportunity to post LINKS OVER A DECADE OLD to claim relevance to the present. Seriously, that CNET link was from 2003. Last major release of AIX was in 2014, after that ComputerWorld article. So far IBM had made no indicate that AIX is discontinued.
As for operating systems, IBM does have another OS that runs on POWER: OS/400 (aka IBM i). That got a major update six years ago.
The power 8 might be higher performance per core and higher performance per clock, but it also uses more power and costs more, while not being natively x86 compatible (a negligible point for the target market, but a point none the less.
Either way it's a wash. The power 8 has higher cost of ownership, the Intel is slower. Nothing really surprising about that statement.
Considering that enterprise software is typically licensed on a per core basis, having fewer but faster cores would lead to a lower cost of ownership. Sure, the initial hardware cost and energy consumption might be higher but these are dwarfed by software licensing fees.
This does put POWER8 at a bit of a disadvantage for running open source software where there is no large scale licensing. Here POWER8 has to be significantly faster to offset those two factors. POWER8 is faster than many of the Intel alternatives but arguably not fast enough to offset the IBM hardware prices (the Tyan POWER8 systems perhaps) and energy consumption.
Then there are cheap, highly energy efficient chips like Xeon D that'll keep POWER8 out of the low end of the server market. If IBM is going to push openPOWER it needs a chip like the PPC 970 again to compete in that area while the bigger POWER8 chips tackle the Xeon E5/E7.
"...The power 8 has higher cost of ownership, the Intel is slower..."
Not really correct. The POWER8 has higher cost of ownership AND being slowest in the cpu arena. Both Intel and SPARC is faster than POWER8, and they are both cheaper.
"...Eh? The POWER8 is besting Intel in both performance per core and performance per clock..."
Intel scores 715 in SPECint2006 and IBM POWER8 scores 642. I fail to see how POWER8 cpu is faster than Intel cpus in SPECint2006? The same thing in SPECfp2006, Intel is faster too. I fail to see how POWER8 is faster than x86 in either SPECfp2006 or SPECint2006? But maybe you have seen other benchmarks that prove the opposite, in that case you are free to post them. If not, x86 is faster than POWER8.
Hey Brutalizer, are you a paid astroturfer? I don't get all the hate on POWER. If anything else, we absolutely need to avoid platform hegemony. Intel having the deck stacked entirely in their hands is rife for potential abuse. Having alternatives like ARM and POWER I feel are essential to keep businesses honest.
Additionally, benchmarks can be cooked to favor one arch over another. I'd rather see performance in the real world to make any sort of determination before committing to one over the other.
@mattrock. We dont care about hegemony in the Enterprise. We care about cost, execution and reliability with great customer support. So, INTC so far has all that.
Oracle says Sparc is faster, by posting hard numbers. Look at all the 25 ish benchmarks where SPARC M7 is 2-3x faster all the way up to 11x faster than POWER8. You can not cheat in offically reviewed benchmarks.
I would support "Brutalizer". Every processor has its strength and weakness. If memory architecture is considered, for the same capacity, Intel is conjested memory, IBM is very distributed and Oracle-Sun is something in between. So Intel will always have memory B/W problem every way. IBM has memory efficiency problem. Oracle in theory doesn't have problem, but with 2 dimm per ch, that look like have problem. Oracle-Sun is for highly branched workload in the real world. Intel is for 1T/Core more of single threaded workloads and IBM is for mixed workloads with 2T-4T/Core priority. So supercomputing workloads will work fast on IBM now, compared to intel and sparc, while analytics and graph and other distributed will work faster on SPARC M7 and S7 (although S7 is resource limited). While for intel, a soft mix of applications and highly customized os is better. Leave the business decisions and the sales price. List prices are twice as much as sales price in the real world. These three processors (xeon e5v4, power8-9, sparc m7-s7) are thoroughly tuned for different work spaces with very little overlap. So there's no point in comparing them other than their specs. Its like comparing a falcon and a lion and a swordfish. Their environments are different even though all of them hunt. Thats in the real world. So benchmarks are not the real proof. We at the university of IITD have lots and lots of intel xeon e5v4, some P8 (10-15 single and dual sockets), and a very few (1-2 two socket M7 and 2 two socket S7). We run anything and every thing on any of these, we get our hands on. And this is the real world conclusion. So don't fight. Its a context centric supply of processors!
Because it supports up to 8 threads per core. The primary technologies enabling this are: (a) the design is essentially clustered with two largely identical clusters. In single threaded mode, instructions can route to either cluster, but in 2, 4 or 8 threaded mode, 1, 2 or 4 threads are more or less pinned to a cluster. (b) a 2-level register file design that allows for a massive pool of registers. (c) much finer-grained control over thread performance priorities than Intel offers.
Intel's second thread get's about an extra 25% throughput. IBM's second thread gets about an extra 45% throughput. At 4 threads this rises to about 90..95%, and at 8 threads to about 100%. You can view this as IBM being better at getting performance out of a second thread, or as Intel at better at getting performance out of the first thread. Both are accurate, and represent each company's priorities.
But the bottom line is that for throughput, for most purposes, an Intel 20 core CPU is worth about 20*1.25=25 virtual cores; an IBM 12 core CPU is worth about 12*2=24 virtual cores.
Higher than 2-way SMT is common. Sun/Oracle offer 8-way SMT. Xeon Phi has a form of 4-way SMT. I think even some of the ARM CPUs designed specifically for high-performance networking are 4- or 8-way SMT, but I may be misremembering.
Intel's implementation of SMT (Simultaneous Multi Threading), called by Intel hyperthreading, allows for 2 threads per core. IBM's implementation in POWER8 allows for 8 thread per core (as those are dedicated server CPUs). AMD will introduce their version of SMT with their next architecture, allowing also 2 threads/core.
Interesting that only half of the memory channels are actually used. Though looking at the motherboard, they would have ran out of physical room to put another 32 DIMM slots.
The other thing that stands out are the TDP and clock speeds. The clocks are far lower than other POWER8 systems. This drop in clock speed doesn't lower the TDP that much either.
If the target market is primarily to move data from here to there and back, then lower frequency means cheaper CPUs, with no real effect on performance. (There are simulations that recommend CPUs save power by dropping frequency during stretches of code that are memory dominated,but I don't know if anyone implements this yet. Point is, the simulations show that the performance drop is minimal.)
As for overall power, I'm guessing the CPU power is probably lost in the noise compared to the IO and DRAM power. The CPU power matters from the point of view of not wanting to overheat the CPU (and thereby destroy it), but probably not that much in terms of system power.
Bottom line is, I'm guessing this is a way for IBM to sell off lousy CPU binnings (low frequency and/or too much power/Hz) to a market that can get some value out of them. Which is ultimately a good thing for everyone :-)
Energy consumption being dominated by DIMMs is likely true. Even low balling per DIMM power consumption at 5W per DIMM means that memory would be the largest energy consumer. Having 32 slots attached to a single socket is a lot of memory and that'd only half of what POWER8 can do.
We’ve updated our terms. By continuing to use the site and/or by logging into your account, you agree to the Site’s updated Terms of Use and Privacy Policy.
Facebook
Twitter
RSS
36 Comments
Back to Article
Drumsticks - Thursday, April 7, 2016 - link
That's two new servers in as many days during a pretty high profile time for it. They won't be getting 50% marketshare anytime soon, but Power8 seems to be a good design. NVLink is a nice advantage too; I hope we see a bigger IBM presence in the future.Brutalizer - Thursday, April 7, 2016 - link
POWER8 is not a good design, but you have been tricked by IBM marketing to believe so. For instance, POWER8 in general is slower than the fastest x86 cpu. For instance, in SPEC2006, the E5-2699v3 reaches 715 whereas POWER8 reaches 642. Of course, the SPARC M7 is the record holder with 1200 SPECint2006. Here are all the numbers:https://blogs.oracle.com/BestPerf/entry/201510_spe...
In general the SPARC M7 is 2-3x faster than POWER8 or x86, all the way up to 11x faster. In the link above are 25ish different benchmarks such as databases, SPECjbb2005, Hadoop Terasort, Neural networks, etc etc. Just read the benchmarks.
I dont really understand why anybody would want to sell POWER8 servers, as they are slower than x86 and more expensive?
-POWER6 was several times faster than x86 and costed 10x more
-POWER7 was 10-20% faster than x86 and costed 3x more
-POWER8 is slower than x86 and still more expensive?
This is bad news for POWER, as IBM only does high margin business and walks away from low margin business. And POWER9 must be cheaper than x86 because it will be slower. Nobody will buy POWER anymore.
Oh BTW, IBM has officially said that AIX will be killed off. AIX runs on POWER, so without AIX, why sell slow POWER servers?
http://www.cnet.com/news/ibm-linux-is-the-logical-...
"...Asked whether IBM's eventual goal is to replace AIX with Linux, Mills responded, "It's fairly obvious we're fine with that idea...It's the logical successor."
http://www.computerworld.com/article/2474897/linux...
Better learn Linux boys.
name99 - Thursday, April 7, 2016 - link
You're comparing Intel's just released to IBM's two years old. And you're assuming that the performance characteristics of IBM's target audience (on the one hand, very large data HPC, on the other hand very large I-footprint business code) match SPEC2006. These are both dubious assumptions.POWER8+ will probably be released soon, with enough tweaks (frequency and cache, probably) to match x86; while POWER9 will have 24 cores.
Meanwhile Google continues to look into POWER as a possible CPU for some of its servers (perhaps in the context of driving nV GPUs for AI neural networks). Intel kinda sorta has a vague plan to counter things like nVLink through either using Xeon Phi or one day shipping a Xeon with an on-board FPGA, but it's not clear that either of these solutions is absolutely superior to IBM's solutions.
Phil_Oracle - Friday, April 8, 2016 - link
How is Power8+ going to get frequency & cache improvements when the process isn't changing (its still at 22nm)? While Power8 was "announced" in August 2013, real 12-core Power8 chips delivered in systems didn’t get announced till April 2015, almost 2 years later. If anything, I believe IBM will just trickle down the higher GHZ Power8's @ the higher GHzes down to the lower end systems, where currently the weaker Power8's are today. Maybe even installing 12-core Power8 onto DCM's to double-up the core count per system.Brutalizer - Friday, April 8, 2016 - link
"...POWER8+ will probably be released soon, with enough tweaks (frequency and cache, probably) to match x86; while POWER9 will have 24 cores...."Well, if POWER8+ can match x86 it is good for IBM. But I doubt that. Intel is not resting, and when POWER8+ arrives, there will be new Xeons, even faster. And cheaper. So, why would anyone buy POWER8+? Oh, if you want to loose money big time.
name99 - Friday, April 8, 2016 - link
POWER8+ (apparently now renamed "POWER8 with NVLink") will arrive this year. This year's Xeon's have already arrived. So we will probably have parity of the newest Xeons (the largest E7 v4's) with the POWER8's of the next few months.Next year POWER9 will be on 14nm FF (compare with 22nm today). So huge process improvement, obviously being used to double density, and likely either increase per-core resources or bump up frequency slightly.
Meanwhile next year's Skylake Xeons will be on 14nm FF (just like this year's Broadwell Xeons) so no process improvement, and just a few percentage points micro-architecture performance improvement. Which means that for 2017 POWER9 is likely to be way ahead of Skylake Xeon.
At some point, of course, Intel will eventually move to 10 nm. But the Kaby Lake delays show that their process improvement has slowed down. They might have two years or so of 10nm before GF get there --- but they will likely use those two years shipping first mobile then desktop, so the Xeon's at 10nm will arrive maybe only a few months before 2020's POWER10.
A second interesting aspect, as yet not clear, is whether POWER will have the chance to explode like ARM has done by having Chinese [or even Japanese] third parties design their own SoCs around a basic POWER core. This seems to be what IBM wants to happen, but I don't think the actual plan specifics are public knowledge. Obviously there are a different set of diificulties in translating the design for a core (or whatever IBM sells) into a full SoC from doing the same with an ARM core targeting mobile. But I could imagine that the Chinese government would be willing to subsidize at least one company to do the necessary research. And it's even possible that Fujitsu might decide this is a more useful path going forward than continuing with SPARC.
Of course these are simply theories, but I don't think they're utterly crazy. If IBM could reinvent (part of) itself as something like an ARM for HPC, that might be good enough to keep POWER viable for quite a few more years.
Vatharian - Tuesday, April 12, 2016 - link
Is NVLink is going to be exclusive to IBM arch?milli - Thursday, April 7, 2016 - link
You conveniently forget to mention that you're comparing a 32 core (M7) and 18 core (Intel) CPU to a 10 core Power8 CPU.Also, the Power8 CPU is very close to the Intel chip in SPECfp.
Its per core performance is the highest of the three under SPEC_rate.
Phil_Oracle - Friday, April 8, 2016 - link
And for Database workloads like OLTP, running the open source HammerDB benchmark test, based on TPC-C, shows SPARC M7, with its 32-cores, outperforms 4 x Power8's totaling 24-cores by 37%, therefore showcasing higher performance/core. SPARC M7 also surpassed a dual-Xeon E5-2699 v3 with 36-cores total by a whopping 38%, showcasing a 55% performance/core advantage. https://blogs.oracle.com/BestPerf/entry/20160317_s...Theres several other real-world benchmarks showcasing SPARC M7 better performance/core. And even Power9 won't be 24-cores till atleast 2018!
milli - Friday, April 8, 2016 - link
Phil_Oracle giving me an Oracle link with benchmarks done by Oracle to put the Oracle SPARC M7 in a nice spotlight.Brutalizer - Friday, April 8, 2016 - link
@milliWhat has the number of cores to do anything? I am talking about which CPU is fastest, not which core is fastest. And when we compare cpu to cpu, Intel x86 is faster than POWER8.
So my point still holds; I dont understand why anyone would buy a slow POWER8 when they can buy a faster x86? And cheaper. x86 gives more performance for a cheaper sum. There is absolutely no reason anyone would want to migrate from fast cheap x86, to slow and expensive POWER8.
Kevin G - Thursday, April 7, 2016 - link
Eh? The POWER8 is besting Intel in both performance per core and performance per clock. That is incredibly impressive. The examples in the link you cite as fast require far more cores to reach those performance levels.Wow, you never miss an opportunity to post LINKS OVER A DECADE OLD to claim relevance to the present. Seriously, that CNET link was from 2003. Last major release of AIX was in 2014, after that ComputerWorld article. So far IBM had made no indicate that AIX is discontinued.
As for operating systems, IBM does have another OS that runs on POWER: OS/400 (aka IBM i). That got a major update six years ago.
Samus - Friday, April 8, 2016 - link
The power 8 might be higher performance per core and higher performance per clock, but it also uses more power and costs more, while not being natively x86 compatible (a negligible point for the target market, but a point none the less.Either way it's a wash. The power 8 has higher cost of ownership, the Intel is slower. Nothing really surprising about that statement.
Kevin G - Friday, April 8, 2016 - link
Considering that enterprise software is typically licensed on a per core basis, having fewer but faster cores would lead to a lower cost of ownership. Sure, the initial hardware cost and energy consumption might be higher but these are dwarfed by software licensing fees.This does put POWER8 at a bit of a disadvantage for running open source software where there is no large scale licensing. Here POWER8 has to be significantly faster to offset those two factors. POWER8 is faster than many of the Intel alternatives but arguably not fast enough to offset the IBM hardware prices (the Tyan POWER8 systems perhaps) and energy consumption.
Then there are cheap, highly energy efficient chips like Xeon D that'll keep POWER8 out of the low end of the server market. If IBM is going to push openPOWER it needs a chip like the PPC 970 again to compete in that area while the bigger POWER8 chips tackle the Xeon E5/E7.
Brutalizer - Friday, April 8, 2016 - link
"...The power 8 has higher cost of ownership, the Intel is slower..."Not really correct. The POWER8 has higher cost of ownership AND being slowest in the cpu arena. Both Intel and SPARC is faster than POWER8, and they are both cheaper.
Here are SPEC2006 results, convince yourself that POWER8 is slowest:
https://blogs.oracle.com/BestPerf/entry/201510_spe...
satai - Sunday, April 10, 2016 - link
Do you really consider Oracle blog a good source of information in such a discussion?Brutalizer - Friday, April 8, 2016 - link
"...Eh? The POWER8 is besting Intel in both performance per core and performance per clock..."Intel scores 715 in SPECint2006 and IBM POWER8 scores 642. I fail to see how POWER8 cpu is faster than Intel cpus in SPECint2006? The same thing in SPECfp2006, Intel is faster too. I fail to see how POWER8 is faster than x86 in either SPECfp2006 or SPECint2006? But maybe you have seen other benchmarks that prove the opposite, in that case you are free to post them. If not, x86 is faster than POWER8.
mattrock1988 - Friday, April 8, 2016 - link
Hey Brutalizer, are you a paid astroturfer? I don't get all the hate on POWER. If anything else, we absolutely need to avoid platform hegemony. Intel having the deck stacked entirely in their hands is rife for potential abuse. Having alternatives like ARM and POWER I feel are essential to keep businesses honest.SovietRambo - Saturday, April 9, 2016 - link
He is a known Sun/Oracle troll named Kebbabert. Who trolls on numerous forums and message boards. If he is not paid, then thats just sad.Kevin G - Monday, April 11, 2016 - link
He has been invited to a Sun holiday party at some point per his previous posts:http://it24.idg.se/2.2275/1.202161/staende-ovation...
Perhaps not paid but had gotten some benefits at the very least.
mattrock1988 - Friday, April 8, 2016 - link
Additionally, benchmarks can be cooked to favor one arch over another. I'd rather see performance in the real world to make any sort of determination before committing to one over the other.Vlad_Da_Great - Saturday, April 9, 2016 - link
@mattrock. We dont care about hegemony in the Enterprise. We care about cost, execution and reliability with great customer support. So, INTC so far has all that.close - Friday, April 8, 2016 - link
Oracle says Sparc is faster. Wonder why...Brutalizer - Friday, April 8, 2016 - link
Oracle says Sparc is faster, by posting hard numbers. Look at all the 25 ish benchmarks where SPARC M7 is 2-3x faster all the way up to 11x faster than POWER8. You can not cheat in offically reviewed benchmarks.satai - Sunday, April 10, 2016 - link
But you can easily choose a benchark you are going to publish...RISC is RISKY! - Tuesday, August 2, 2016 - link
I would support "Brutalizer". Every processor has its strength and weakness. If memory architecture is considered, for the same capacity, Intel is conjested memory, IBM is very distributed and Oracle-Sun is something in between. So Intel will always have memory B/W problem every way. IBM has memory efficiency problem. Oracle in theory doesn't have problem, but with 2 dimm per ch, that look like have problem. Oracle-Sun is for highly branched workload in the real world. Intel is for 1T/Core more of single threaded workloads and IBM is for mixed workloads with 2T-4T/Core priority. So supercomputing workloads will work fast on IBM now, compared to intel and sparc, while analytics and graph and other distributed will work faster on SPARC M7 and S7 (although S7 is resource limited). While for intel, a soft mix of applications and highly customized os is better. Leave the business decisions and the sales price. List prices are twice as much as sales price in the real world. These three processors (xeon e5v4, power8-9, sparc m7-s7) are thoroughly tuned for different work spaces with very little overlap. So there's no point in comparing them other than their specs. Its like comparing a falcon and a lion and a swordfish. Their environments are different even though all of them hunt. Thats in the real world. So benchmarks are not the real proof. We at the university of IITD have lots and lots of intel xeon e5v4, some P8 (10-15 single and dual sockets), and a very few (1-2 two socket M7 and 2 two socket S7). We run anything and every thing on any of these, we get our hands on. And this is the real world conclusion. So don't fight. Its a context centric supply of processors!colinstu - Thursday, April 7, 2016 - link
great if you need a bunch of ram in a system but don't need that many cores.F@st - Thursday, April 7, 2016 - link
Why POWER8 12-Core has 96 threads not 24 like Intel's?SlakeDK - Thursday, April 7, 2016 - link
I believe it is because Power8 has 8 threads or SMT - Simultaneous Multi-Threading. At least that is the case for the original IBM Power8 servers.name99 - Thursday, April 7, 2016 - link
Because it supports up to 8 threads per core. The primary technologies enabling this are:(a) the design is essentially clustered with two largely identical clusters. In single threaded mode, instructions can route to either cluster, but in 2, 4 or 8 threaded mode, 1, 2 or 4 threads are more or less pinned to a cluster.
(b) a 2-level register file design that allows for a massive pool of registers.
(c) much finer-grained control over thread performance priorities than Intel offers.
Intel's second thread get's about an extra 25% throughput.
IBM's second thread gets about an extra 45% throughput. At 4 threads this rises to about 90..95%, and at 8 threads to about 100%.
You can view this as IBM being better at getting performance out of a second thread, or as Intel at better at getting performance out of the first thread. Both are accurate, and represent each company's priorities.
But the bottom line is that for throughput, for most purposes, an Intel 20 core CPU is worth about 20*1.25=25 virtual cores; an IBM 12 core CPU is worth about 12*2=24 virtual cores.
Higher than 2-way SMT is common. Sun/Oracle offer 8-way SMT. Xeon Phi has a form of 4-way SMT. I think even some of the ARM CPUs designed specifically for high-performance networking are 4- or 8-way SMT, but I may be misremembering.
frenchy_2001 - Thursday, April 7, 2016 - link
Intel's implementation of SMT (Simultaneous Multi Threading), called by Intel hyperthreading, allows for 2 threads per core. IBM's implementation in POWER8 allows for 8 thread per core (as those are dedicated server CPUs).AMD will introduce their version of SMT with their next architecture, allowing also 2 threads/core.
F@st - Friday, April 8, 2016 - link
Thanks SlakeDK, name99, frenchy_2001.Kevin G - Thursday, April 7, 2016 - link
Interesting that only half of the memory channels are actually used. Though looking at the motherboard, they would have ran out of physical room to put another 32 DIMM slots.The other thing that stands out are the TDP and clock speeds. The clocks are far lower than other POWER8 systems. This drop in clock speed doesn't lower the TDP that much either.
name99 - Friday, April 8, 2016 - link
If the target market is primarily to move data from here to there and back, then lower frequency means cheaper CPUs, with no real effect on performance. (There are simulations that recommend CPUs save power by dropping frequency during stretches of code that are memory dominated,but I don't know if anyone implements this yet. Point is, the simulations show that the performance drop is minimal.)As for overall power, I'm guessing the CPU power is probably lost in the noise compared to the IO and DRAM power. The CPU power matters from the point of view of not wanting to overheat the CPU (and thereby destroy it), but probably not that much in terms of system power.
Bottom line is, I'm guessing this is a way for IBM to sell off lousy CPU binnings (low frequency and/or too much power/Hz) to a market that can get some value out of them. Which is ultimately a good thing for everyone :-)
Kevin G - Friday, April 8, 2016 - link
Energy consumption being dominated by DIMMs is likely true. Even low balling per DIMM power consumption at 5W per DIMM means that memory would be the largest energy consumer. Having 32 slots attached to a single socket is a lot of memory and that'd only half of what POWER8 can do.SlakeDK - Friday, April 8, 2016 - link
And also so IBM can differentiate with their Power8 servers :)