Re: Mathematica 8

*To*: mathgroup at smc.vnet.net*Subject*: [mg114036] Re: Mathematica 8*From*: Bill Rowe <readnews at sbcglobal.net>*Date*: Mon, 22 Nov 2010 07:33:59 -0500 (EST)

On 11/20/10 at 12:25 PM, sydgeraghty at me.com (Syd Geraghty) wrote: >On Nov 20, 2010, at 3:11 AM, Bill Rowe wrote: >>On 11/19/10 at 5:07 AM, sydgeraghty at me.com (Syd Geraghty) wrote: >>>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 >>I see bit better with my MacBookPro, an overall score of 0.60. >Do you have 4 GB RAM? I only have 2 GB. I have 6 GB of RAM installed. >>>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). >>Could you elaborate a bit on this? I thought to make use of more >>than one core I needed to use commands like Parallelize. Are >>modifying the benchmarking code? >No ... I just selected to launch parallel kernels on startup of Mathematica 8 >in Mathematica Preferences. >Then I just ran MathematicaMark8 with no code modifications to see >what happened. So, I gave this a try and the benchmark score for me rises to 0.89. That prompted me to look at the code. The code looks at the value of $KernelCount. If Positive[$KernelCount] returns true, the benchmarks are run using parallel computing. This is done using DistributeDefinitions, ParallelMap etc. It is useful to know the benchmarking package can be used to benchmark multiple cores. It would have been better if this were documented in the package guide for benchmarking. And while this does give users a transparent way to benchmark multiple cores, it doesn't give users a transparent way to make use of parallel computing.