New article: Bulldozer benchmark analysis

Article: Bulldozer Benchmarks, What Do They Mean?
By: David Kanter (dkanter.delete@this.realworldtech.com), March 30, 2011 9:25 am
Room: Moderated Discussions
NaN (spam@googlemail.com) on 3/30/11 wrote:
---------------------------
>Well, first thanks for your helpful comparison despite the >"useless" benchmarks.

Yeah, don't get me started on the tests. The suite they were using is a half-assed pile of junk. There are things I dislike a lot about SPEC, but their benchmarks are a model of clarity in comparison (even without having source code available). It's also amusing how many of the tests were very small toy benchmarks or had horrible coding practices (based on commentary I had seen).

>You stated in your article on p. 1:
>> 'The Interlagos benchmarks were compiled with GCC 4.5.2 – which is generally
>inferior compiler to commercial products from Intel, Pathscale or the Portland Group.'
>
>The statement that GCC is inferior to commercial products is obviously not true.
>It depends on the work you want to do and application field. My experience is that
>e.g. the Intel compiler produces fast floating point code out of the box. You already
>mentioned the compiler flags. In GCC 4.5.x you have to specify the right compiler
>flags like '-ffast-math -fno-finite-math-only' beside O3 to get a fast and useful
>result. In newer releases of GCC the default optimizations (with O3) are more safe
>and therefore slower so you have to enable some additional optimizations to get
>optimal performance and the right result. ICC is good at auto-vectorization and
>has well optimized library functions but even with a few optimizations enabled it is nearly sure you break ieee
>-754 compliance. Helping GCC a little bit can boost performance over that, which
>you are able to get with the Intel compiler. On integer workloads it depends on
>the code which compiler is superior (my experience). Many workgroups in my university
>do not use the Intel compiler because it even won't compile old code or does sometimes
>strange things (not because of programming errors, perhaps because of bugs in optimization
>routines or too agressive optimizations). Even Agner Fog sees GCC as one of the
>best optimizing compilers. Furthermore, no one should compile a program with the
>Intel compiler and distribute the executables if one has >not overwritten cpu detection
>routines so that the optimal code path is used for AMD >cpus, too.

I don't entirely disagree with you. GCC can be a very reasonable compiler. However, it's simply not used for many benchmarks - presumably because the code quality is lower than the commercial alternatives.

So from the standpoint of benchmarks available in source form, I definitely do see it as inferior to the commercial compilers. When I start seeing benchmarking practices change, then I'll re-assess my opinion.

My point is that using a different compiler could gain you a modest amount of performance, which means that if anything these benchmarks will tend to understand Bulldozer's perf.

>@benchmarks: GCC 4.5 seems to have no support for AVX and >Bulldozer optimizations
>therefore there should be some improvements with GCC 4.6. >Another question is whether
>the fma4 flag was used in the benchmarks.

Thanks for that. I suspected that might be the case, but I was not really sure. Yet another reason why these benchmarks really represent a worst case.

David
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TopicPosted ByDate
New article: Bulldozer benchmark analysisDavid Kanter2011/03/30 02:27 AM
  New article: Bulldozer benchmark analysisNaN2011/03/30 07:47 AM
    New article: Bulldozer benchmark analysisDavid Kanter2011/03/30 09:25 AM
      New article: Bulldozer benchmark analysisdc2011/03/30 12:07 PM
      New article: Bulldozer benchmark analysisFoo_2011/03/30 12:17 PM
        New article: Bulldozer benchmark analysisDavid Kanter2011/03/30 01:34 PM
          BD won't "kick in" until 2.5GHzBaronMAtrix2011/03/31 08:37 AM
            BD won't "kick in" until 2.5GHzDavid Kanter2011/03/31 09:21 AM
              He is an AMDZone lunaticNIKOLAS2011/04/01 06:40 AM
                See how he behaves hereDavid Kanter2011/04/01 08:08 AM
                He is an AMDZone lunatichorsefly2011/04/02 05:46 AM
                  This is not relevantDavid Kanter2011/04/02 09:16 AM
                  Post removedDavid Kanter2011/04/02 12:39 PM
          New article: Bulldozer benchmark analysisanonymous2011/04/04 05:08 AM
      New article: Bulldozer benchmark analysisinterested2011/04/01 03:28 PM
        New article: Bulldozer benchmark analysisDavid Kanter2011/04/01 03:53 PM
          New article: Bulldozer benchmark analysisNaN2011/04/02 07:12 AM
            New article: Bulldozer benchmark analysisDavid Kanter2011/04/02 09:05 AM
              New article: Bulldozer benchmark analysisNaN2011/04/02 09:24 AM
                New article: Bulldozer benchmark analysisDavid Kanter2011/04/02 12:36 PM
                  AMD's Open64 compiler ?Alex2011/04/04 02:23 AM
                    AMD's Open64 compiler ?David Kanter2011/04/04 08:19 AM
                      AMD's Open64 compiler ?Richard Cownie2011/04/04 09:52 AM
                        AMD's Open64 compiler ?David Kanter2011/04/04 01:20 PM
                          AMD's Open64 compiler ?none2011/04/04 02:25 PM
                        AMD's Open64 compiler ?gallier22011/04/04 11:06 PM
                          thanks, very interesting (NT)Richard Cownie2011/04/05 03:44 AM
                          AMD's Open64 compiler ?Andreas Stiller2011/04/05 08:23 AM
                        AMD's Open64 compiler ?Vincent Diepeveen2011/04/06 01:11 AM
                      AMD's Open64 compiler ?Vincent Diepeveen2011/04/06 01:01 AM
                        AMD's Open64 compiler ?none2011/04/06 01:41 AM
                          AMD's Open64 compiler ?Vincent Diepeveen2011/04/07 02:02 PM
                            AMD's Open64 compiler ?Brett2011/04/07 04:55 PM
                              AMD's Open64 compiler ?Megol2011/04/09 11:03 AM
                                Clang+LLVMBrett2011/04/11 10:51 PM
                                  Clang+LLVMRob Thorpe2011/04/12 12:52 AM
                                    Clang+LLVMBrett2011/04/12 08:27 PM
                                      I prefer my dollars exponential, not cubic (NT)David Kanter2011/04/12 11:34 PM
                                        I prefer cubic meters of euros over cubic feet of dollarsJouni Osmala2011/04/13 01:13 AM
                                          Life is not about money, but about power (and informational asymetry)?2011/04/18 01:14 AM
                                      Clang+LLVMRob Thorpe2011/04/13 10:37 AM
                                        Clang+LLVMLinus Torvalds2011/04/13 11:47 AM
                                          Clang+LLVMRob Thorpe2011/04/13 01:46 PM
                                            Clang+LLVMLinus Torvalds2011/04/13 04:40 PM
                                              Clang+LLVManon2011/04/13 07:31 PM
                                                Clang+LLVMLinus Torvalds2011/04/14 06:11 AM
                                              Clang+LLVMRob Thorpe2011/04/14 12:33 PM
                                                Clang+LLVMLinus Torvalds2011/04/14 12:48 PM
                                                  Clang+LLVMAndi Kleen2011/04/14 06:38 PM
                                                    Clang+LLVMJouni Osmala2011/04/14 09:54 PM
                                                  Clang+LLVM?2011/04/14 11:56 PM
                                                    Clang+LLVMLinus Torvalds2011/04/15 06:23 AM
                                                      Clang+LLVM?2011/04/15 10:11 PM
                                                        Clang+LLVMLinus Torvalds2011/04/16 08:10 AM
                                                          Clang+LLVMLinus Torvalds2011/04/16 08:32 AM
                                                            Competing for speed?2011/04/16 11:47 PM
                                                            Clang+LLVMEduardoS2011/04/17 12:38 PM
                                                              Clang+LLVMLinus Torvalds2011/04/17 02:00 PM
                                                                Competing for speed?2011/04/17 10:57 PM
                                                                  Competing for speedLinus Torvalds2011/04/18 09:07 AM
                                                                    Competing for speedanon2011/04/18 05:38 PM
                                                                      Competing for speedLinus Torvalds2011/04/18 07:24 PM
                                                                        Competing for speedanon2011/04/19 05:05 AM
                                                                          Competing for speedanon2011/04/21 01:35 PM
                                                                            Competing for speedLinus Torvalds2011/04/22 11:09 AM
                                                                    Competing for speed?2011/04/18 11:45 PM
                                                                      Competing for speedLinus Torvalds2011/04/19 06:41 AM
                                                                        Competing for speedLinus Torvalds2011/04/19 07:46 AM
                                                                        Oh ... the irony?2011/04/19 10:36 AM
                                                                          Oh ... the ironyLinus Torvalds2011/04/19 01:49 PM
                                                                            What's the speedup?iz2011/04/19 10:54 PM
                                                                              What's the speedup?Linus Torvalds2011/04/20 06:48 AM
                                                                            Oh ... the irony?2011/04/23 05:52 AM
                                                                          Oh ... the ironyDougal2011/04/20 06:23 AM
                                                                            Oh ... the irony?2011/04/25 12:05 PM
                                                                              Oh ... the ironyDougal2011/04/26 05:22 AM
                                                                                Oh ... the irony?2011/04/27 12:14 AM
                                                  Clang+LLVMRob Thorpe2011/04/16 01:23 PM
                                                    Clang+LLVManon2011/04/16 03:01 PM
                                                      Clang+LLVMRob Thorpe2011/04/18 04:53 AM
                                                        Clang+LLVManon2011/04/18 05:28 PM
                                        Clang+LLVMPaul2011/04/14 10:43 AM
                                  Clang+LLVMFoo_2011/04/12 05:36 AM
                              AMD's Open64 compiler ?Paul2011/04/10 02:50 AM
                                C++ front-endsDavid Kanter2011/04/10 06:29 AM
                                  C++ front-endsPaul2011/04/10 07:19 AM
                                    C++ front-endsanonymous2011/04/10 07:28 AM
                                      C++ front-endsnone2011/04/10 07:36 AM
                                      C++ front-endsPaul2011/04/10 07:44 AM
                                    C++ front-endsMichael S2011/04/10 07:47 AM
                                      C++ front-endsnone2011/04/10 07:51 AM
                                      C++ front-endsRob Thorpe2011/04/10 11:13 AM
                                        C++ front-endsPaul2011/04/11 10:07 AM
                                AMD's Open64 compiler ?Konrad Schwarz2011/04/14 01:06 AM
                              Testing Clang + LLVMVincent Diepeveen2011/04/20 06:31 AM
                                Does your program crash when compiled with -O0? (NT)Michael S2011/04/20 10:11 AM
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                                Testing Clang + LLVMMegol2011/04/20 11:05 AM
                                  Testing Clang + LLVMVincent Diepeveen2011/04/20 11:43 AM
                                    Testing Clang + LLVMstubar2011/04/20 12:23 PM
                                      Testing Clang + LLVMVincent Diepeveen2011/04/20 12:42 PM
                                        Testing Clang + LLVMRob Thorpe2011/04/20 02:30 PM
                                          Testing Clang + LLVMahnoun2011/04/20 03:13 PM
                                            Testing Clang + LLVMMark Roulo2011/04/20 04:05 PM
                                              Testing Clang + LLVMMegol2011/04/22 04:30 AM
                                    Testing Clang + LLVMahnoun2011/04/20 02:31 PM
                                      Testing Clang + LLVMVincent Diepeveen2011/04/21 02:17 AM
                                        Testing Clang + LLVMnone2011/04/21 02:36 AM
                                        Testing Clang + LLVMahnoun2011/04/21 11:02 AM
                                          Testing Clang + LLVMMichael S2011/04/21 12:01 PM
                                            Testing Clang + LLVMMichael S2011/04/21 03:29 PM
                                              Testing Clang + LLVMBrett2011/04/21 04:49 PM
                                              Testing Clang + LLVMEduardoS2011/04/22 02:22 PM
                                                Testing Clang + LLVMMichael S2011/04/23 09:59 AM
                                            Testing Clang + LLVMDavid Ball2011/04/21 06:43 PM
                                Testing Clang + LLVMBrett2011/04/20 12:54 PM
                            AMD's Open64 compiler ?Megol2011/04/09 10:49 AM
                              Imperative compilers (and the lack of it)?2011/04/10 12:36 AM
                                Imperative compilers (and the lack of it)?2011/04/10 12:43 AM
                                Imperative compilers (and the lack of it)Paul2011/04/10 02:37 AM
                                  Imperative compilers (and the lack of it)?2011/04/10 05:30 AM
                                  Imperative compilers (and the lack of it)Vincent Diepeveen2011/04/10 06:20 AM
                                  Imperative compilers (and the lack of it)Gabriele Svelto2011/04/11 08:24 AM
                                  Imperative compilers (and the lack of it)Michael S2011/04/12 12:12 AM
                                    Imperative compilers (and the lack of it)?2011/04/12 01:41 AM
                                      Imperative compilers (and the lack of it)EduardoS2011/04/12 03:13 PM
                                        U+269BMichael S2011/04/13 12:45 AM
                                          U+269B?2011/04/13 03:52 AM
                                            U+269BBrendan2011/04/20 07:18 AM
                                              U+269BMichael S2011/04/20 09:11 AM
                                                U+269BHeath Provost2011/04/20 10:26 AM
                                                  You are right, Heath. Sorry, Brannon.Michael S2011/04/20 10:42 AM
                                                    Sorry again, Brendan (NT)Michael S2011/04/20 10:43 AM
                                                    Testing western non-us letters.Jouni Osmala2011/04/20 09:41 PM
                                                      Those show up fine to me (NT)David Kanter2011/04/21 07:48 AM
                                                      Testing western non-us letters.Heath Provost2011/04/21 11:15 AM
                                                        Testing western non-us letters.EduardoS2011/04/22 02:14 PM
                                                          Testing western non-us letters.Heath Provost2011/04/22 03:21 PM
                                                            Testing western non-us letters.EduardoS2011/04/22 04:24 PM
                                                            We actually upgraded to 2008 R2David Kanter2011/04/22 10:23 PM
                                                              We actually upgraded to 2008 R2EduardoS2011/04/22 10:33 PM
                                                                We actually upgraded to 2008 R2rwessel2011/04/22 11:11 PM
                                                                  We actually upgraded to 2008 R2David Kanter2011/04/22 11:28 PM
                                                                    We actually upgraded to 2008 R2Ricardo B2011/04/23 09:43 AM
                                                                      We actually upgraded to 2008 R2David Kanter2011/04/23 10:31 AM
                                                                    We actually upgraded to 2008 R2sparkplug2011/04/23 08:25 PM
                                                                      We actually upgraded to 2008 R2David Kanter2011/04/24 03:36 PM
                                                                        We actually upgraded to 2008 R2anon2011/04/24 06:32 PM
                                                                          We actually upgraded to 2008 R2David Kanter2011/04/24 11:12 PM
                                                                        We actually upgraded to 2008 R2EduardoS2011/04/24 08:10 PM
                                                                          We actually upgraded to 2008 R2David Kanter2011/04/24 11:04 PM
                                                                        We actually upgraded to 2008 R2anonymous2011/04/24 08:44 PM
                                                                          We actually upgraded to 2008 R2David Kanter2011/04/24 10:57 PM
                                                                        File size optimizationsjrl2011/04/25 02:03 AM
                                                                          File size optimizationsRicardo B2011/04/25 07:14 AM
                                                                            File size optimizationsjrl2011/04/25 05:52 PM
                                                                          File size optimizationsDavid Kanter2011/04/25 07:49 AM
                                                                            File size optimizationsRicardo B2011/04/25 08:22 AM
                                                                              ContinuationRicardo B2011/04/25 08:25 AM
                                                                              File size optimizationsChristian Packmann2011/04/25 09:56 AM
                                                                                File size optimizationsEduardoS2011/04/25 11:57 AM
                                                                                  File size optimizationsRicardo B2011/04/25 01:01 PM
                                                                            File size optimizationsEduardoS2011/04/25 12:01 PM
                                                                            Javascript is at the root of the latency problemjrl2011/04/25 06:03 PM
                                                                          File size optimizationsEduardoS2011/04/25 12:14 PM
                                                                            File size optimizationsrwessel2011/04/25 12:49 PM
                                                                              File size optimizationsEduardoS2011/04/25 12:57 PM
                                                                            File size optimizationsjrl2011/04/25 05:54 PM
                                                                              A simple approachSilent2011/04/25 09:24 PM
                                                                                Show Thread exists but the default is Yes (NT)Silent2011/04/25 09:26 PM
                                                                          File size optimizationsHeath Provost2011/04/25 02:02 PM
                                    Imperative compilers (and the lack of it)Azazel2011/04/12 08:23 PM
                                Imperative compilers (and the lack of it)none2011/04/10 06:00 AM
                                  Imperative compilers (and the lack of it)dmsc2011/04/10 06:39 AM
                                  Imperative compilers (and the lack of it)EduardoS2011/04/10 12:55 PM
                                compiler failure rateshobold2011/04/10 10:55 AM
                                  compiler failure rates?2011/04/10 11:13 PM
                                    compiler failure rateshobold2011/04/11 05:07 AM
                                Imperative compilers (and the lack of it)EduardoS2011/04/10 12:55 PM
                                  Imperative compilers (and the lack of it)?2011/04/10 11:13 PM
                                    Imperative compilers (and the lack of it)Konrad Schwarz2011/04/14 01:28 AM
                                      Imperative compilers (and the lack of it)gallier22011/04/14 04:47 AM
                                      Imperative compilers (and the lack of it)EduardoS2011/04/14 02:04 PM
                                        Imperative compilers (and the lack of it)Konrad Schwarz2011/04/15 03:43 AM
                                Hard register problemsRob Thorpe2011/04/11 12:14 AM
                                  Hard register problemsMax2011/04/11 03:05 PM
                                    Hard register problemsRob Thorpe2011/04/11 03:28 PM
                                Imperative compilers (and the lack of it)gallier22011/04/11 09:26 AM
                                  I wonder why.j2011/04/11 10:39 PM
                                    I wonder why.?2011/04/11 11:44 PM
                                Imperative compilers (and the lack of it)nksingh2011/04/12 11:00 PM
                                  Imperative compilers (and the lack of it)?2011/04/12 11:23 PM
                              AMD's Open64 compiler ?Vincent Diepeveen2011/04/10 06:06 AM
                                AMD's Open64 compiler ?none2011/04/10 07:23 AM
                                  AMD's Open64 compiler ?Eugene Nalimov2011/04/11 03:57 PM
                                    AMD's Open64 compiler ?EduardoS2011/04/12 02:55 PM
                                AMD's Open64 compiler ?Megol2011/04/10 11:05 PM
                                  AMD's Open64 compiler ?Vincent Diepeveen2011/04/20 12:52 PM
                                    Yap transform? What is it? (NT)Michael S2011/04/21 09:04 AM
                                      Yap transform? What is it? (NT)Vincent Diepeveen2011/04/22 02:56 AM
                    AMD's Open64 compiler ?Vincent Diepeveen2011/04/05 12:02 PM
    New article: Bulldozer benchmark analysisNaN2011/03/30 05:24 PM
      New article: Bulldozer benchmark analysisChris2011/04/05 03:33 AM
  New article: Bulldozer benchmark analysisdc2011/03/30 08:09 AM
    New article: Bulldozer benchmark analysisMS2011/03/30 08:53 AM
      New article: Bulldozer benchmark analysisDaniel Bizo2011/03/31 12:20 AM
        New article: Bulldozer benchmark analysisanun2011/03/31 02:48 AM
    New article: Bulldozer benchmark analysisAlex2011/03/30 09:18 AM
      New article: Bulldozer benchmark analysisIntelUser20002011/03/30 01:19 PM
    New article: Bulldozer benchmark analysisGroo2011/03/31 06:14 AM
      New article: Bulldozer benchmark analysisanon2011/03/31 08:29 AM
        AMD's memory controllers are fineDavid Kanter2011/03/31 09:27 AM
          AMD's memory controllers are fineanon2011/04/05 11:24 AM
            AMD's memory controllers are fineanon2011/04/05 04:52 PM
              AMD's memory controllers are fineVincent Diepeveen2011/04/06 01:36 AM
                AMD's memory controllers are fineanon2011/04/06 06:59 AM
                  AMD's memory controllers are fineVincent Diepeveen2011/04/07 02:15 PM
                    AMD's memory controllers are fineVincent Diepeveen2011/04/07 02:27 PM
                      AMD's memory controllers are fineanon2011/04/07 02:57 PM
                    AMD's memory controllers are fineanon2011/04/07 02:54 PM
        New article: Bulldozer benchmark analysisAzazel2011/03/31 09:54 AM
        New article: Bulldozer benchmark analysisAlex2011/03/31 11:38 PM
      New article: Bulldozer benchmark analysisanon2011/04/01 03:23 AM
    Streaming conflicts can lead to performance degradationsgc2011/04/08 06:35 AM
  AMD's probe filterAndreas Stiller2011/04/05 08:37 AM
  a waste of timeMoritz2011/04/09 07:01 AM
    a waste of timehorsefly2011/04/09 03:34 PM
      a waste of timeDavid Kanter2011/04/09 06:56 PM
        a waste of timehorsefly2011/04/10 05:13 AM
          InvestorsDavid Kanter2011/04/10 06:27 AM
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