Strange slow performance on macbook pro

*To*: mathgroup at smc.vnet.net*Subject*: [mg111596] Strange slow performance on macbook pro*From*: Sebastian Szwarc <beyonder7 at tlen.pl>*Date*: Sat, 7 Aug 2010 01:29:50 -0400 (EDT)

Hi, On Mathematica 7.0.1 I've noticed several strange behaviours regarding to time of calculations. I have MBP 2,56 4GB RAM (late 2009 model). I compared some notebooks with my friend computers (4 cores amd similar cpu freq) that is 2x faster than mine, however: -matrix multiplication is over 6 times slower on my machine I also installed windows 7 on my computer and used Karl benchmarks. It looks that Timing[Eigenvalues[Table[Random[],{1200},{1200}]]][[1]] and Timing[Sum[ 2/\[Pi] Integrate[Log[2 Cos[x/2]]*Cos[n x], {x, 0, \[Pi]}], {n, 0, 15}]][[1]] works siginificantly slower on macos for unknown reason. Also in the latter when I did calculations first time it resulted in Out[12]= 30.6088 again was 3, again 1,49 so after 3rd run is faster 20 times! Anyone noticed some similar behaviour or have some explanation on this? I could find any relevant information on Wolfram Tech Forum :(( regards Sebastian