Mike,
I can't say I have benchmarked this myself, but I am guessing there would be only a small performance advantage, as memory access would be the bottleneck. I don't know if each HyperThreaded CPU has its own memory cache.
Nick
On Sat, 2007-10-13 at 21:43 -0500, Michael Harms wrote:
Hello,
Question about eking out maximum machine performance: Is there a performance advantage (or alternatively penalty) for running twice as many FreeSurfer jobs (simultaneously) as physical CPUs on a Linux machine with HyperThreading enabled CPUs? That is, say you have two physical cores with HyperThreading -- the Linux OS treats this as four logical processors. However, given that Freesurfer is very 'execute' intensive is there any advantage to be gained by running 4 rather than 2 FS jobs simultaneously? Or will the total time per brain with 4 simultaneous jobs be (on average) just twice as long?
thanks, Mike H.