Article: Knights Landing CPU Speculation
By: Mark Roulo (nothanks.delete@this.xxx.com), November 20, 2013 11:43 am
Room: Moderated Discussions
Daniel (x.delete@this.y.z) on November 19, 2013 3:28 am wrote:
> Eric (eric.kjellen.delete@this.gmail.com) on November 18, 2013 1:17 pm wrote:
> > David Kanter (dkanter.delete@this.realworldtech.com) on November 18, 2013 3:03 am wrote:
> > > Knights Landing is Intel’s first clean sheet redesign of the Larrabee family, targeted at throughput
> > > computing and manufactured on a 14nm process with products expected in late 2014 or early 2015.
> > > The adoption of AVX3, on-package embedded DRAM, and bootable products have been disclosed, but
> > > most details are unknown. This article analyzes the options available for the Knights Landing
> > > CPU core and explains why Intel’s existing cores are a poor fit for the target workloads, concluding
> > > that the most likely outcome is a new custom core for Knights Landing.
> > >
> > > http://www.realworldtech.com/knights-landing-cpu-speculation/
> > >
> > > Questions, comments and discussion are welcome!
> > >
> > > David
> >
> > Great article, about one my favorite areas in this field. I recalled another article I read where
> > some Intel executive stated that future versions of what would be Xeon Phi were going to be based
> > on Atom cores and I found one in The Register from 2011 where Justin Rattner does address this issue:
> > "But in the future, MIC will be based on Atom cores, and then the integer gap between Xeon and MIC
> > will start to close." http://www.theregister.co.uk/2011/09/15/intel_rattner_mic_coprocessor/
> >
> > So going by this and by what you said about Bonnell not having been productized (I don't know
> > if research silicon maybe has been fabbed though) on 22nm or 14nm, presumably upcoming Xeon
> > Phi generations have been developed in parallel with and in connection to development on the
> > future Atom cores (i.e. not Bonnell) and the KNC cores cores will be based on them, but as in
> > the case of the P54C derivative extended with a 512-bit vector unit and other adaptations.
>
> Heise (http://www.heise.de/newsticker/meldung/Intels-Supercomputer-Beschleuniger-Xeon-Phi-mit-72-Kernen-integriertem-InfiniBand-und-3-TFlops-DGEMM-2049668.html)
> claims KNL using 72 Cores based on an extended Silvermont architecture now featuring OoO FPUs. I wonder how reliable
> their Sources are, because ~3TF with just 72 Cores would result in (boost) clocks above 2.5GHz.
The way the numerics folks score flops, they treat a multiply-accumulate operation as two floating point instructions.
So ... single-precision (32-bit wide) instructions on the 512 wide vectors gives us 16 floats per clock.
72 cores x 16 floats x 2 ops/clock = 2,304 ops/clock for the entire chip.
1.3 GHz will get you to 3 TFLOP. 1.3 GHz is quite plausible.
Does anyone actually believe that the only instructions running will be single-precision multiply-accumulate? No, but this is a peak number, not something that normal people will see (also, you might get close to it if you are doing mostly matrix multiply).
> Eric (eric.kjellen.delete@this.gmail.com) on November 18, 2013 1:17 pm wrote:
> > David Kanter (dkanter.delete@this.realworldtech.com) on November 18, 2013 3:03 am wrote:
> > > Knights Landing is Intel’s first clean sheet redesign of the Larrabee family, targeted at throughput
> > > computing and manufactured on a 14nm process with products expected in late 2014 or early 2015.
> > > The adoption of AVX3, on-package embedded DRAM, and bootable products have been disclosed, but
> > > most details are unknown. This article analyzes the options available for the Knights Landing
> > > CPU core and explains why Intel’s existing cores are a poor fit for the target workloads, concluding
> > > that the most likely outcome is a new custom core for Knights Landing.
> > >
> > > http://www.realworldtech.com/knights-landing-cpu-speculation/
> > >
> > > Questions, comments and discussion are welcome!
> > >
> > > David
> >
> > Great article, about one my favorite areas in this field. I recalled another article I read where
> > some Intel executive stated that future versions of what would be Xeon Phi were going to be based
> > on Atom cores and I found one in The Register from 2011 where Justin Rattner does address this issue:
> > "But in the future, MIC will be based on Atom cores, and then the integer gap between Xeon and MIC
> > will start to close." http://www.theregister.co.uk/2011/09/15/intel_rattner_mic_coprocessor/
> >
> > So going by this and by what you said about Bonnell not having been productized (I don't know
> > if research silicon maybe has been fabbed though) on 22nm or 14nm, presumably upcoming Xeon
> > Phi generations have been developed in parallel with and in connection to development on the
> > future Atom cores (i.e. not Bonnell) and the KNC cores cores will be based on them, but as in
> > the case of the P54C derivative extended with a 512-bit vector unit and other adaptations.
>
> Heise (http://www.heise.de/newsticker/meldung/Intels-Supercomputer-Beschleuniger-Xeon-Phi-mit-72-Kernen-integriertem-InfiniBand-und-3-TFlops-DGEMM-2049668.html)
> claims KNL using 72 Cores based on an extended Silvermont architecture now featuring OoO FPUs. I wonder how reliable
> their Sources are, because ~3TF with just 72 Cores would result in (boost) clocks above 2.5GHz.
The way the numerics folks score flops, they treat a multiply-accumulate operation as two floating point instructions.
So ... single-precision (32-bit wide) instructions on the 512 wide vectors gives us 16 floats per clock.
72 cores x 16 floats x 2 ops/clock = 2,304 ops/clock for the entire chip.
1.3 GHz will get you to 3 TFLOP. 1.3 GHz is quite plausible.
Does anyone actually believe that the only instructions running will be single-precision multiply-accumulate? No, but this is a peak number, not something that normal people will see (also, you might get close to it if you are doing mostly matrix multiply).
Topic | Posted By | Date |
---|---|---|
Knights Landing CPU Speculation | David Kanter | 2013/11/18 03:03 AM |
Knights Landing CPU Speculation | none | 2013/11/18 03:59 AM |
Knights Landing CPU Speculation | Patrick Chase | 2013/11/23 04:18 PM |
Knights Landing CPU Speculation | Adam Kalisz | 2013/11/26 02:20 AM |
Over 2,000 mm^2 of eDRAM??? | Mark Roulo | 2013/11/26 10:28 AM |
Over 2,000 mm^2 of eDRAM??? | David Kanter | 2013/11/26 12:09 PM |
Over 2,000 mm^2 of eDRAM??? | Eric Bron | 2013/11/26 12:21 PM |
Over 2,000 mm^2 of eDRAM??? | tarlinian | 2013/11/26 12:50 PM |
Over 2,000 mm^2 of eDRAM??? | Eric Bron | 2013/11/26 02:07 PM |
Over 2,000 mm^2 of eDRAM??? | Eric Bron | 2013/11/26 02:09 PM |
Over 2,000 mm^2 of eDRAM??? | aaron spink | 2013/11/26 04:03 PM |
Over 2,000 mm^2 of eDRAM??? | Eric Bron | 2013/11/27 12:42 AM |
Over 2,000 mm^2 of eDRAM??? | aaron spink | 2013/11/27 11:31 AM |
Over 2,000 mm^2 of eDRAM??? | David Kanter | 2013/11/26 05:25 PM |
Over 2,000 mm^2 of eDRAM??? | tarlinian | 2013/11/26 08:01 PM |
Over 2,000 mm^2 of eDRAM??? | Eric | 2013/11/27 03:54 AM |
eDRAM is DRAM in a logic-oriented process | Paul A. Clayton | 2013/11/27 08:10 AM |
Knights Landing CPU Speculation | James | 2013/11/18 06:26 AM |
Knights Landing CPU Speculation | Michael S | 2013/11/18 03:57 PM |
Knights Landing CPU Speculation | Urban Novak | 2013/11/19 01:49 AM |
Knights Landing CPU Speculation | none | 2013/11/19 02:19 AM |
Knights Landing CPU Speculation | Eric | 2013/11/19 08:48 PM |
Total GPGPU/Xeon Phi market maybe ~ $500M/year ... | Mark Roulo | 2013/11/20 11:35 AM |
Knights Landing CPU Speculation | Wes Felter | 2013/11/19 01:06 PM |
Knights Landing CPU Speculation | Michael S | 2013/11/19 01:49 PM |
Knights Landing CPU Speculation | Eric | 2013/11/18 01:17 PM |
Knights Landing CPU Speculation | Daniel | 2013/11/19 03:28 AM |
Knights Landing CPU Speculation | Eric | 2013/11/19 08:36 PM |
HPC guys score FLOPS non-obviously | Mark Roulo | 2013/11/20 11:43 AM |
3-TFlops-DGEMM | Michael S | 2013/11/20 11:59 AM |
3-TFlops-DGEMM | Mark Roulo | 2013/11/20 01:22 PM |
3-TFlops-DGEMM | Daniel | 2013/11/20 02:04 PM |
3-TFlops-DGEMM | Eric | 2013/11/21 02:28 AM |
3-TFlops-DGEMM | Michael S | 2013/11/21 06:48 AM |
3-TFlops-DGEMM | RecessionCone | 2013/11/21 12:13 PM |
3-TFlops-DGEMM | Michael S | 2013/11/21 03:34 PM |
3-TFlops-DGEMM | Eric | 2013/11/22 03:10 AM |
3-TFlops-DGEMM | Michael S | 2013/11/22 05:41 AM |
A (not very sensible) alternative: FMADD + FADD | Paul A. Clayton | 2013/11/22 09:19 AM |
3-TFlops-DGEMM | Sylvain Collange | 2013/11/24 03:37 AM |
3-TFlops-DGEMM | Michael S | 2013/11/24 07:06 AM |
3-TFlops-DGEMM | Sylvain Collange | 2013/11/24 10:28 AM |
HPC guys score FLOPS non-obviously | Patrick Chase | 2013/11/23 03:58 PM |
Knights Landing CPU Speculation | Paul Caheny | 2013/11/18 02:25 PM |
Knights Landing CPU Speculation | Konrad Schwarz | 2013/11/19 01:24 AM |
Knights Landing CPU Speculation | Amiba Gelos | 2013/11/19 08:36 PM |
Knights Landing CPU Speculation | David Kanter | 2013/11/20 10:52 AM |
Knights Landing CPU Speculation | Linus Torvalds | 2013/11/21 03:12 PM |
Knights Landing CPU Speculation | Amiba Gelos | 2013/11/21 06:14 PM |
Knights Landing CPU Speculation | Patrick Chase | 2013/11/23 04:33 PM |
Knights Landing CPU Speculation | Linus Torvalds | 2013/11/25 12:29 PM |
Knights Landing CPU Speculation | Linus Torvalds | 2013/11/25 01:05 PM |
Knights Landing CPU Speculation | Patrick Chase | 2013/11/25 01:22 PM |
Knights Landing CPU Speculation | Linus Torvalds | 2013/11/26 11:11 AM |
Knights Landing CPU Speculation | Eric | 2013/11/26 04:05 AM |
Knights Landing CPU Speculation | Eric | 2013/11/26 04:15 AM |
Knights Landing CPU Speculation | none | 2013/11/26 04:33 AM |
Knights Landing CPU Speculation | Eric | 2013/11/26 07:30 PM |
Knights Landing CPU Speculation | Eric | 2013/11/26 07:34 PM |
What is MCDRAM? | anon | 2013/11/26 09:58 PM |
What is MCDRAM? | none | 2013/11/27 02:00 AM |
What is MCDRAM? | Klimax | 2013/11/27 03:19 AM |
Knights Landing CPU Speculation | Klimax | 2013/11/27 12:06 AM |
Knights Landing CPU Speculation | Klimax | 2013/11/27 12:05 AM |
Knights Landing CPU Speculation | anon | 2013/11/26 06:53 AM |
Knights Landing CPU Speculation | none | 2013/11/26 07:20 AM |
Knights Landing CPU Speculation | Michael S | 2013/11/26 09:06 AM |
Knights Landing CPU Speculation | none | 2013/11/26 10:18 AM |
Knights Landing CPU Speculation | Eric Bron | 2013/11/26 02:21 PM |
Knights Landing CPU Speculation | Eric Bron | 2013/11/26 02:27 PM |
Knights Landing CPU Speculation | none | 2013/11/26 03:26 PM |
Knights Landing CPU Speculation | anon | 2013/11/26 06:42 PM |
Knights Landing CPU Speculation | none | 2013/11/27 02:08 AM |
Knights Landing CPU Speculation | anon | 2013/11/27 02:50 AM |
Knights Landing CPU Speculation | none | 2013/11/27 02:58 AM |
Knights Landing CPU Speculation | Michael S | 2013/11/27 02:25 AM |
Knights Landing CPU Speculation | anon | 2013/11/27 03:32 AM |
Knights Landing CPU Speculation | Michael S | 2013/11/27 04:08 AM |
Knights Landing CPU Speculation | Chung Leong | 2013/11/27 02:28 AM |
Knights Landing CPU Speculation | Michael S | 2013/11/27 03:53 AM |
Knights Landing CPU Speculation | Chung Leong | 2013/11/27 02:03 PM |
BiG.LiTTLe for KNL? | Jeff K | 2013/11/22 07:17 AM |
BiG.LiTTLe for KNL? | Patrick Chase | 2013/11/23 03:54 PM |
BiG.LiTTLe for KNL? | Patrick Chase | 2013/11/23 04:01 PM |
Transactional memory | Patrick Chase | 2013/11/23 03:37 PM |
Transactional memory | Bhima | 2013/11/25 08:01 AM |
Transactional memory | Patrick Chase | 2013/11/25 12:52 PM |
Knights Landing CPU Speculation | Daniel | 2013/11/25 03:17 AM |
Knights Landing CPU Speculation | Klimax | 2013/11/25 04:12 AM |
Knights Landing CPU Speculation | none | 2013/11/25 05:05 AM |
Knights Landing CPU Speculation | Klimax | 2013/11/25 05:45 AM |
Knights Landing CPU Speculation | none | 2013/11/25 05:55 AM |
Knights Landing CPU Speculation | gmb | 2013/11/25 08:21 AM |