As in Syd's results, the machine name was changed when using the 2-kernel configuration at startup. The benchmark result improved from 0.474 in Case 1, to 0.674 in Case 2, a 42% improvement (Syd got a 61% improvement).
I am puzzled, however, by the fact that the total time for Case 1 was 29.19 (presumably seconds) whereas the total time for Case 2 was 123.17. Thus, Case 2 took a lot longer to complete than Case 1, yet the performance improved. Can anyone explain this?
On Nov 19, 2010, at 2:07 AM, Syd Geraghty wrote:
> Murray, > > I second your call for discussion which could lead to better informed hardware buying decisions to run Mathematica 8 optimally. > > For those of us with an overwhelming desire to continue using Apple's MAC OSX systems the current situation (as I understand it so far) is that Mathematica 8 GPU support strategy leaves behind a large installed base of Intel Mac systems built until very recently when MacBooks switched to nVidia GPUs and iMacs used the more recent ATI GPUs (ATI Radeon HD 4670, HD 5670 & HD 5750). > > The wonderful part of Mathematica 8 strategy is the terrific incentive for one to buy some new hardware with (one hopes) scintillating speed improvements. > > So lets look for some data to support the buying decision! Using MathematicaBenchmark8 with my current machine: > > Machine Name: sydsmacbookpro > System: MacOS X V 10.6.5 Snow Leopard (64-bit) > Date: November 15, 2010 > Mathematica Version: 8.0.0 > Benchmark Result: 0.41 > > Compare this to the current overall best and the Apple system best: > > 3.07 GHz Core i7-950 (8 Cores) 1.00 > Windows 7 Pro (64-bit) Desktop > > 3.06 GHz Core 2 Duo E8435 (2 Cores) 0.73 > iMac OS X Snow Leopard (64-bit) Desktop > > 2 * 2.26 GHz Quad Core Xeon E5520 (8 Cores) 0.69 > Mac XServe OS X (64-bit) Server > > The interesting fact is if I set up Mathematica 8 to use both of my MacBooks cores to I get a 61% MathematicaBenchmark8 improvement (an impressive result). > > Machine Name: 2-node homogeneous cluster > System: MacOS X V 10.6.5 Snow Leopard (64-bit) > Date: November 15, 2010 > Mathematica Version: 8.0.0 > Benchmark Result: 0.66 > > Note that Mathematica assigned the name "2-node homogeneous cluster" to my "parallel MacBook". > > So the disappointing first comparison from my current system (best result of .66 using Mathematica 8 to the best MathematicaBenchmark8 result of 1.0) apparently limits my available upgrade in performance to 52%. > > Now this is clearly nonsense. But without getting into the benchmark writing business it is the best one can do currently with WRI tools. > > I hope someone at WRI will recognize the importance of totally upgrading benchmarking to take into account support for GPUs (and address the CUDA vs OpenCL issues) and parallelism (multi-core, multi-thread) support. Without a serious benchmark upgrade I fear the general discussion will not lead to actionable information. > > My current conclusion with Apple products is that the best and safest hardware upgrade (for me) to optimize use of Mathematica 8 would be to go Apple Mac Pro with the latest nVidia GPU cards to be able to use CUDA (assuming $$s unconstrained). > > My preference for a number of reasons (including cost), however, would be the 27" iMac which has ATI HD 5750 graphics. > > Mathematica 8 docs say the HD 5750 is "supported" with Mathematica 8 OpenCL. The problem is there is no documentation I have found so far that gives me a comparison of what that means vs going nVidia and CUDA. > > Any input from WRI and other MathGroup aficionados would be greatly appreciated. > > Yours truly ... Syd Geraghty > > Syd Geraghty B.Sc., M.Sc. > email@example.com > San Jose, CA > > Mathematica 8.0 for Mac OS X x86 (64-bit) (November 6, 2010) > Licenses: L2983-5890, L3028-2592 > MacOS X V 10.6.5 Snow Leopard > MacBook Pro 2.33 Ghz Intel Core 2 Duo 2GB RAM > > On Nov 18, 2010, at 4:05 AM, Murray Eisenberg wrote: > >> I'd like to see some discussion in this group about >> advantages/disadvantages of CUDA vs. OpenCL, especially when used in >> conjunction with Mathematica 8? I'll have to upgrade my hardware from >> an ATI board that's too old to support OpenCL, so I want to choose >> wisely between ATI and nVidia, with now Mathematica 8 in the picture. > >