HTT/SMP

Stephen Montgomery-Smith stephen at math.missouri.edu
Tue Mar 1 00:39:23 GMT 2005


I have a dual Xeon system, for which I had hyperthreading enabled.  I 
was running a CPU intensive floating point program (specifically using 
the fftw3 port with threads).  I found that using 4 (hyper) processors 
really did give me a speed advantage, even though I do find web sites 
that suggested this advantage was minimal.  (So for example, 4 processes 
on this system seemed to run at the equivalent of 2GHz on these 3GHz 
computers, so the advantage was about 1.3 times.)

But then after about a day the computer had a panic.  I found that 4 
CPU's under FreeBSD 5.3 is apparently unstable, and there were 
statements to the effect that this would be fixed in FreeBSD 5.4.  Is 
this going to happen?  I am currently running a rather recent version of 
FreeBSD 5.3-Stable, maybe a week or two old, so I am concerned that 
maybe this won't get committed.

Thanks, Stephen


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