GPU raw H/W only has about a 10x advantage over a CPU

Article: Parallelism at HotPar 2010
By: Michael S (already5chosen.delete@this.yahoo.com), August 2, 2010 2:31 pm
Room: Moderated Discussions
Mark Roulo (nothanks@xxx.com) on 8/2/10 wrote:
---------------------------
>AM (myname4rwt@jee-male.com) on 8/2/10 wrote:
>---------------------------
>>David Kanter (dkanter@realworldtech.com) on 7/29/10 wrote:
>>---------------------------
>>...
>>>When I hear crap like "the only interesting workloads are amenable to GPUs", it's
>>>quite annoying. Ditto for claimed 100X speed ups.
>
>
>>And since you are apparently calling crap all 100x and higher speedups, it's reasonable
>>to ask if you have any proof wrt every piece of published research with such results.
>>I don't think you have any though.
>
>The raw compute advantage of an nVidia Fermi GPU vs. a 6-core Intel CPU is in the 10x range.
>
>The raw bandwidth advantage is in the 4x to 5x range.
>
>The GPU is less flexible.
>
>I would suggest that when a paper claims a 10x to 20x speed increase above the
>raw hardware advantage, it is up to the paper authors to explain where this advantage came from.
>
>I've been doing GPU programming for about one year now, and
>having looked at a number of these papers (and wandered around the nVidia GPGPU
>conference one year), I can say that the vast majority of the papers claiming more
>than 4-5x performance do it using one or more of the following techniques:
>
>1) Use only one CPU core,
>2) Use scalar CPU code,
>3) Fail to strip-mine the CPU code for good cache locality,
>4) Use a better algorithm on the GPU (e.g. N3 for the CPU, N log (N) for the GPU).
>
>I have seen examples of all four, with (1)-(3) being the most common (and these three often appear together).
>
>My back-of-the-envelope guesstimate is that going from 1 core to 6 on the CPU is
>worth 4x to 6x (we can use 5x as a nice middle ground), using the vector unit is
>4x, and strip-mining can get you 2x or more. Put them together and you get 5x4x2
>= 40x speedup of well optimized CPU code versus simple scalar code. If the GPU
>is being compared to a CPU running simple scalar code, you might see a 100x to 200x
>claim, but this will turn into a 2½x to 5x claim if run against well optimized CPU code.
>
>It is clearly unreasonable to expect David (or anyone else) to read every paper
>claiming unrealistic speedups, but the hardware just isn't there for the GPU to
>see more than about 10x. When the underlying hardware can't do something that it
>is claimed to do, I think the burden of proof properly belongs on the people making the claim.
>
>-Mark Roulo
>

comp.arch discussion:
http://groups.google.com/group/comp.arch/browse_frm/thread/5aadb32f1b30a7e4/5424f4f8d89e16e9#5424f4f8d89e16e9

In particular this short message by Terje Mathisen
http://groups.google.com/group/comp.arch/msg/d36a9e35dc31c73c

The link, he provided:
http://gpgpu.org/wp/wp-content/uploads/2009/11/SC09_Seismic_Hess.pdf

Unfortunately, article contains about zero information about reference "CPU" implementation over which they claim a major gain. However they sound honest, article doesn't leave an impression of NVidia-sponsored cheat.

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TopicPosted ByDate
Tarek's Hotpar 2010 article onlineDavid Kanter2010/07/27 07:29 AM
  Tarek's Hotpar 2010 article onlineAnon2010/07/27 01:57 PM
    Tarek's Hotpar 2010 article onlineDavid Kanter2010/07/27 10:48 PM
      Tarek's Hotpar 2010 article onlineAnon2010/07/28 02:44 PM
        Tarek's Hotpar 2010 article onlineanon2010/07/28 04:10 PM
        CPU+GPUDavid Kanter2010/07/29 11:38 AM
          CPU+GPUMark Christiansen2010/07/30 06:36 AM
            CPU+GPUhobold2010/07/30 06:54 AM
              CPU+GPUGabriele Svelto2010/07/30 07:18 AM
                CPU+GPUhobold2010/07/30 02:46 PM
              CPU+GPUAaron Spink2010/08/02 05:32 PM
                CPU+GPUhobold2010/08/03 03:33 AM
                  CPU+GPURicardo B2010/08/03 04:19 AM
            CPU+GPU - the software problemVincent Diepeveen2010/07/31 04:50 PM
              CPU+GPU - the software problemmpx2010/08/02 11:19 AM
                CPU+GPU - the software problemRichard Cownie2010/08/02 12:48 PM
                  CPU+GPU - the software problemGabriele Svelto2010/08/02 11:10 PM
                    CPU+GPU - the software problemhobold2010/08/03 03:41 AM
                      CPU+GPU - the software problemRichard Cownie2010/08/03 05:17 AM
                        CPU+GPU - the software problemhobold2010/08/04 06:45 AM
                          NVidia in a holeRichard Cownie2010/08/04 07:23 AM
                            NVidia in a holeRohit2010/08/04 07:33 AM
                              NVidia in a holeRichard Cownie2010/08/04 07:50 AM
                                NVidia in a holeRohit2010/08/05 06:31 AM
                                  NVidia in a holeGroo2010/08/05 01:08 PM
                                NVidia in a holeGroo2010/08/05 01:07 PM
                              NVidia in a holeMark Roulo2010/08/04 08:26 AM
                                NVidia in a holeLaughabee2010/08/18 07:28 AM
                            Can nVidia survive without a sub-$100 GPU market?Mark Roulo2010/08/04 08:29 AM
                              Can nVidia survive without a sub-$100 GPU market?Richard Cownie2010/08/04 08:42 AM
                                Can nVidia survive without a sub-$100 GPU market?Mark Roulo2010/08/04 08:55 AM
                                  Can nVidia survive without a sub-$100 GPU market?Linus Torvalds2010/08/04 10:35 AM
                                    "profit" is subjectiveRichard Cownie2010/08/04 10:49 AM
                                      "profit" is subjectivea reader2010/08/06 03:54 AM
                                        no price warRichard Cownie2010/08/06 06:18 AM
                                  Can nVidia survive without a sub-$100 GPU market?Aaron Spink2010/08/04 11:19 AM
                                  Can nVidia survive without a sub-$100 GPU market?Konrad Schwarz2010/08/06 07:13 AM
                                CPU lineup != GPU lineupRohit2010/08/05 06:43 AM
                                  CPU lineup != GPU lineupRichard Cownie2010/08/05 07:12 AM
                                    CPU lineup != GPU lineupRohit2010/08/05 07:37 AM
                                      CPU lineup != GPU lineupRichard Cownie2010/08/05 07:56 AM
                                        CPU lineup != GPU lineupRohit2010/08/05 10:19 AM
                                          CPU lineup != GPU lineuphobold2010/08/06 03:08 AM
                                            CPU lineup != GPU lineupRohit2010/08/06 06:24 AM
                                              CPU lineup != GPU lineuphobold2010/08/06 06:41 AM
                              Can nVidia survive without a sub-$100 GPU market?David Hess2010/08/04 10:31 AM
                              Can nVidia survive without a sub-$100 GPU market?Ricardo B2010/08/04 12:16 PM
                              Semiconductor economicsDavid Kanter2010/08/05 08:13 AM
                                Semiconductor economicsRichard Cownie2010/08/05 08:51 AM
                                  NV buying ViA could shake up thingsRohit2010/08/05 10:09 AM
                                    NV buying ViA could shake up thingsRichard Cownie2010/08/05 10:25 AM
                                      Not likelyDavid Kanter2010/08/05 01:39 PM
                                        Not likelyrandom2010/08/05 01:49 PM
                                          Not likelyAaron Spink2010/08/05 02:18 PM
                                        Not likelyGroo2010/08/05 09:05 PM
                                        Not likelyRohit2010/08/06 06:25 AM
                                    NV buying ViA could shake up thingsGroo2010/08/05 09:02 PM
                                    NV buying ViA could shake up thingsehud2010/08/06 12:53 AM
                                      NV buying ViA could shake up thingsRohit2010/08/06 06:30 AM
                                        NV buying ViA could shake up thingsKevin G2010/08/06 04:54 PM
                                          ViA buying NV could shake up thingsBrendan2010/08/19 05:23 AM
                                        NV buying ViA could shake up thingsGroo2010/08/06 07:24 PM
                            NVidia in a holempx2010/08/04 11:01 AM
                              NVidia in a holeRichard Cownie2010/08/04 11:31 AM
                                NVidia in a holercf2010/08/04 02:40 PM
                              NVidia in a holeRohit2010/08/05 06:51 AM
                              NVidia in a holeGroo2010/08/05 08:50 PM
                              NVidia in a holeAaron Spink2010/08/05 10:52 PM
                          Anyone else wish Intel would buy Nvidia ? (NT)Silent2010/08/07 12:30 AM
                            Hell noa2010/08/07 07:37 PM
                        CPU+GPU - the software problemno thanks2010/08/04 06:54 PM
                          CPU+GPU - the software problemJouni Osmala2010/08/05 12:41 AM
                            CPU+GPU - the software problemIntelUser20002010/08/05 06:54 PM
                              CPU+GPU - the software problemJouni Osmala2010/08/05 08:36 PM
                            CPU+GPU - the software problemLinus Torvalds2010/08/06 07:08 AM
                              CPU+GPU - the software problemanonymous2010/08/06 08:39 AM
                                CPU+GPU - the software problemLinus Torvalds2010/08/06 09:56 AM
                                  non-existent Via+NV vs real OntarioRichard Cownie2010/08/06 11:12 AM
                              CPU+GPU - the software problemkoby m.2010/08/07 01:06 AM
                  CPU+GPU - the software problemhobold2010/08/03 03:48 AM
                CPU+GPU - the software problemhobold2010/08/03 03:45 AM
                  CPU+GPU - the software problemRichard Cownie2010/08/03 05:22 AM
          CPU+GPUAnon2010/07/30 08:11 PM
            CPU+GPUanon2010/07/31 02:19 AM
            CPU+GPUAaron Spink2010/08/02 05:45 PM
          100x speedups -- here we go againAM2010/08/02 12:37 AM
            100x speedups -- here we go againanon2010/08/02 02:32 AM
              100x speedups -- here we go againanon2010/08/02 10:14 PM
            GPU raw H/W only has about a 10x advantage over a CPUMark Roulo2010/08/02 08:41 AM
              GPU raw H/W only has about a 10x advantage over a CPUMichael S2010/08/02 02:31 PM
                GPU raw H/W only has about a 10x advantage over a CPUanon2010/08/02 08:36 PM
                  GPU raw H/W only has about a 10x advantage over a CPUMichael S2010/08/02 11:41 PM
                    GPU raw H/W only has about a 10x advantage over a CPUMark Roulo2010/08/03 07:22 AM
                      GPU raw H/W only has about a 10x advantage over a CPURohit2010/08/04 06:08 AM
                      There is reasonable explanation...Jouni Osmala2010/08/04 09:10 PM
                  GPU raw H/W only has about a 10x advantage over a CPUMark Roulo2010/08/03 07:19 AM
              simple reality check for youAM2010/08/03 12:45 AM
                simple reality check for younone2010/08/03 06:27 AM
                  simple reality check for youAM2010/08/03 10:50 PM
                    simple reality check for youanon2010/08/03 11:06 PM
                      simple reality check for youAM2010/08/05 02:51 AM
                        catch the same boat as everyone else next time (NT)anon2010/08/05 03:44 AM
                Simple reality checkDavid Kanter2010/08/03 07:24 AM
                  Simple reality checkGabriele Svelto2010/08/03 09:51 PM
                  Simple reality checkAM2010/08/03 10:57 PM
                    Simple reality checkanon2010/08/03 11:12 PM
                      Simple reality checkAM2010/08/05 02:59 AM
                        Simple reality checkanon2010/08/05 03:47 AM
                          Study the papers, troll (NT)AM2010/08/05 11:01 PM
                    Simple reality checkhobold2010/08/04 04:05 AM
                    Simple reality checkDean Kent2010/08/04 08:30 AM
                      Simple reality checkMark Roulo2010/08/04 08:59 AM
                      Suggestion for David Kanter and Mark RouloAM2010/08/05 02:57 AM
                        Suggestion for David Kanter and Mark Roulonone2010/08/05 03:22 AM
                          Suggestion for David Kanter and Mark RouloAM2010/08/05 11:04 PM
                        Suggestion for David Kanter and Mark Roulonone2010/08/05 03:38 AM
                          Suggestion for David Kanter and Mark Rouloanon2010/08/05 03:43 AM
                            Suggestion for David Kanter and Mark RouloAM2010/08/05 11:11 PM
                              Suggestion for David Kanter and Mark Rouloanon2010/08/06 06:52 AM
                          Suggestion for David Kanter and Mark RouloAM2010/08/05 11:10 PM
                            Suggestion for David Kanter and Mark Roulonone2010/08/06 12:35 AM
                              price doesn't matter only in theories (NT)AM2010/08/09 01:13 AM
                            Not apple4appleMichael S2010/08/06 04:13 AM
                              Not apple4appleAM2010/08/09 01:09 AM
                                Not apple4appleMichael S2010/08/09 03:35 AM
                                  Not apple4appleAM2010/08/10 12:05 AM
                                    Not apple4applenone2010/08/10 12:38 AM
                                      Back to topicAM2010/08/10 11:03 PM
                                      Final note (and some remarks on Intel's paper)AM2010/08/13 03:28 AM
                                        Final note (and some remarks on Intel's paper)none2010/08/13 08:10 AM
                                          Final note (and some remarks on Intel's paper)AM2010/08/16 12:14 AM
                                            Final note (and some remarks on Intel's paper)none2010/08/16 05:29 AM
                                              One example of 1000X shown to be wrong.sea2010/08/16 06:55 PM
                                                You're short of some factsAM2010/08/17 12:13 AM
                                                  Maybe you need to read beyond the PR statementSteve Underwood2010/08/17 01:39 AM
                                                    Maybe you need to read beyond the PR statementGroo2010/08/17 07:18 PM
                                                    check the hw they usedAM2010/08/18 02:33 AM
                                                Please realize what Monte Carlo meansVincent Diepeveen2010/08/18 02:28 AM
                                              Final note (and some remarks on Intel's paper)AM2010/08/17 12:18 AM
                                        Final note (and some remarks on Intel's paper)anon2010/08/14 12:22 AM
                                          Final note (and some remarks on Intel's paper)AM2010/08/16 12:15 AM
                                            Final note (and some remarks on Intel's paper)anon2010/08/16 01:10 PM
                                              Final note (and some remarks on Intel's paper)AM2010/08/17 12:15 AM
                                                Final note (and some remarks on Intel's paper)Michael S2010/08/17 01:58 AM
                                                  Final note (and some remarks on Intel's paper)AM2010/08/18 02:17 AM
                                                    Final note (and some remarks on Intel's paper)gallier22010/08/18 03:52 AM
                                                    Final note (and some remarks on Intel's paper)Michael S2010/08/18 04:33 AM
                                                      Final note (and some remarks on Intel's paper)Gabriele Svelto2010/08/18 05:11 AM
                                                      Final note (and some remarks on Intel's paper)Steve Underwood2010/08/18 03:03 PM
                                                        Intel might be moving from ISA to platformhobold2010/08/19 02:58 AM
                                                          Intel might be moving from ISA to platformSteve Underwood2010/08/22 06:00 PM
                                                            Intel might be moving from ISA to platformAnon2010/08/22 09:43 PM
                                                              Intel might be moving from ISA to platformajensen2010/08/22 11:37 PM
                                                                Intel might be moving from ISA to platformMichael S2010/08/23 01:13 AM
                                                                  Intel might be moving from ISA to platformSteve Underwood2010/08/23 01:35 AM
                                                                  Intel might be moving from ISA to platformhobold2010/08/26 03:37 AM
                                                                Intel might be moving from ISA to platformAnon2010/08/23 02:47 PM
                                                              Intel might be moving from ISA to platformSteve Underwood2010/08/23 01:25 AM
                                                                Intel might be moving from ISA to platformhobold2010/08/23 02:03 AM
                                                                  Intel might be moving from ISA to platformSteve Underwood2010/08/23 03:26 AM
                                                                Intel might be moving from ISA to platformAnon2010/08/23 02:55 PM
                                                                Intel might be moving from ISA to platformrwessel2010/08/23 05:41 PM
                                                                  Intel might be moving from ISA to platformSteve Underwood2010/08/23 06:30 PM
                                                                    Intel might be moving from ISA to platformrwessel2010/08/23 08:50 PM
                                                                      Intel might be moving from ISA to platformSteve Underwood2010/08/23 09:34 PM
                                                                        Intel might be moving from ISA to platformrwessel2010/08/24 12:03 AM
                                                              Intel might be moving from ISA to platformIan Ollmann2010/08/23 08:21 PM
                                                          Intel might be moving from ISA to platformajensen2010/08/22 09:36 PM
                                                            Intel might be moving from ISA to platformIan Ollmann2010/08/23 08:45 PM
                                                      Final note (and some remarks on Intel's paper)AM2010/08/19 12:29 AM
                                                        Final note (and some remarks on Intel's paper)Richard2010/08/19 03:51 AM
                                                          I stand corrected.Michael S2010/08/19 04:30 AM
                simple reality check for youanonymous2010/08/03 09:25 AM
                  simple reality check for youAM2010/08/03 10:47 PM
                    simple reality check for youanonymous2010/08/04 09:17 AM
                      simple reality check for youanon2010/08/04 07:33 PM
                      SPECint/FPAM2010/08/05 02:49 AM
                  simple reality check for youRohit2010/08/13 07:31 PM
                    simple reality check for youhobold2010/08/16 05:29 AM
              maybe texture caches ?Richard Cownie2010/08/03 08:27 AM
                maybe texture caches ?none2010/08/03 08:59 AM
                  maybe texture caches ?Richard Cownie2010/08/03 09:15 AM
                    maybe texture caches ?Mark Roulo2010/08/03 09:23 AM
                      maybe texture caches ?Richard Cownie2010/08/03 09:33 AM
                        maybe texture caches ?Mark Roulo2010/08/03 09:37 AM
                          the Hess paperRichard Cownie2010/08/03 10:16 AM
                    maybe texture caches ?Aaron Spink2010/08/03 12:23 PM
                      maybe texture caches ?Mark Roulo2010/08/03 03:13 PM
                        maybe texture caches ?Michael S2010/08/04 12:47 AM
                  maybe texture caches ?Michael S2010/08/03 09:23 AM
                maybe texture caches ?Mark Roulo2010/08/03 09:19 AM
                  maybe texture caches ?Richard Cownie2010/08/03 09:42 AM
                Cache to cache comparisonDavid Kanter2010/08/03 11:28 AM
                  Cache to cache comparisonRichard Cownie2010/08/03 11:52 AM
                    Cache to cache comparisonDavid Kanter2010/08/03 12:21 PM
                      Cache to cache comparisonRichard Cownie2010/08/03 02:55 PM
                      Cache to cache comparisonGabriele Svelto2010/08/03 10:23 PM
                        Nehalem vs Core2Richard Cownie2010/08/04 03:24 PM
                          Nehalem vs Core2IntelUser20002010/08/04 06:26 PM
                          Nehalem vs Core2Gabriele Svelto2010/08/04 09:51 PM
                            Nehalem vs Core2Richard Cownie2010/08/05 02:27 AM
                              Nehalem vs Core2Gabriele Svelto2010/08/05 05:00 AM
                                Nehalem vs Core2Richard Cownie2010/08/05 06:10 AM
                                  Nehalem vs Core2Gabriele Svelto2010/08/05 06:41 AM
                                    Nehalem vs Core2Michael S2010/08/05 09:02 AM
                              Nehalem vs Core2Michael S2010/08/05 09:12 AM
                          Nehalem vs Core2Michael S2010/08/04 11:36 PM
                            Nehalem vs Core2Richard Cownie2010/08/05 07:33 AM
                              Nehalem vs Core2Michael S2010/08/05 08:44 AM
                                Nehalem vs Core2Richard Cownie2010/08/05 09:03 AM
                                  Nehalem vs Core2Michael S2010/08/05 03:21 PM
                                    Nehalem vs Core2Richard Cownie2010/08/05 06:15 PM
                                      I'm wrong, you're right - i's 2 dieRichard Cownie2010/08/05 06:21 PM
                                    Nehalem vs Core2Richard Cownie2010/08/06 07:12 AM
                                      Nehalem vs Core2Michael S2010/08/06 07:33 AM
                                      Nehalem L1 cache latency a hedge for higher clock speeds?Mark Roulo2010/08/06 07:36 AM
                                        Nehalem L1 cache latency a hedge for higher clock speeds?Kevin G2010/08/07 09:14 AM
                                          Nehalem L1 cache latency a hedge for higher clock speeds?IntelUser20002010/08/07 01:32 PM
                                        Nehalem L1 cache latency a hedge for higher clock speeds?someone2010/08/07 01:35 PM
                          difference between C2D/C2Q chipsetsMichael S2010/08/04 11:57 PM
                          Nehalem core goals ... my takeMark Roulo2010/08/06 06:53 AM
                            Bulldozer single-threadRichard Cownie2010/08/06 03:05 PM
                          Nehalem vs Core2Carlie Coats2010/08/07 07:41 AM
                            scalingMichael S2010/08/07 10:12 AM
                            why X5460?Michael S2010/08/07 10:12 AM
                              why X5460?Carlie Coats2010/08/08 03:34 AM
                                why X5460?Michael S2010/08/08 03:42 AM
                                  Polling/PIO based COMM libraries?Michael S2010/08/08 04:14 AM
                    Cache to cache comparisonAnts Aasma2010/08/04 09:00 AM
                      Cache to cache comparisonRichard Cownie2010/08/04 09:08 AM
                        Cache to cache comparisonAnts Aasma2010/08/04 10:28 AM
                      Cache to cache comparisonMichael S2010/08/04 10:33 AM
                        Cache to cache comparisonMark Roulo2010/08/04 11:29 AM
                          Cache to cache comparisonAnts Aasma2010/08/04 12:10 PM
                            Fermi and G200 instruction latencyMark Roulo2010/08/04 01:10 PM
                              Fermi and G200 instruction latencyAnts Aasma2010/08/04 02:01 PM
                        Cache to cache comparisonAnts Aasma2010/08/04 12:00 PM
                        Register read comparisonDavid Kanter2010/08/05 08:16 AM
                          Register read comparisonGabriele Svelto2010/08/05 10:42 PM
                maybe texture caches ?Aaron Spink2010/08/03 12:17 PM
              GPU raw H/W only has about a 10x advantage over a CPURichard2010/08/09 03:58 AM
                GPU raw H/W only has about a 10x advantage over a CPUnone2010/08/09 04:19 AM
                  GPU raw H/W only has about a 10x advantage over a CPUVincent Diepeveen2010/08/24 06:18 AM
                    Forget it, they won't hear itanon2010/08/24 03:37 PM
                    GPU raw H/W only has about a 10x advantage over a CPURichard2010/08/25 12:03 PM
                This forum supports pre tagMichael S2010/08/09 05:03 AM
    Tarek's Hotpar 2010 article onlineRich Vuduc2010/07/28 09:24 AM
      Tarek's Hotpar 2010 article onlineAnon2010/07/28 03:18 PM
  Low hanging fruitMoritz2011/02/03 11:20 AM
    Low hanging fruitJukka Larja2011/02/06 04:01 AM
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