Byron, On May 16, 2006, at 8:34 PM, Byron Ellis wrote:
> Apparently somebody was having some performance issues > > http://sekhon.berkeley.edu/macosx/ > > fortunately, it got dugg and someone fixed it for us > > http://ridiculousfish.com/blog/archives/2006/05/16/36/ > > In an unsurprising turn of events it turns out to be malloc's fault. > It also looks like the build isn't against an optimized BLAS? > We had a discussion about this earlier, it started with https://stat.ethz.ch/pipermail/r-sig-mac/2006-March/002722.html What it boils down to is that ptATLAS can give you a good speed-up, but it can also screw you up by calling malloc/free all the time - it depends on the task. For single core CPUs it's definitely better to use R's own BLAS. For Core Duos it depends on the size of the problem - for bigger problems ptATLAS is better, for smaller problems internal BLAS may be better. In a quiet minute I'll try to run our benchmarks with Lea's allocator and see if it would make sense to use it for OS X. Thanks, Simon _______________________________________________ R-SIG-Mac mailing list R-SIG-Mac@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-mac
