[gmx-users] PowerMac Quad Performance

[David van der Spoel]

Tyler Luchko wrote:
> Hello everybody,
> 
> Has anyone had any experience running GROMACS on a PowerMac Quad  
> machine? We have purchased one as a test but have seen very poor  
> performance when running the benchmarks.  For example, I have  compared 
> the results of the d.villin benchmark from the web with that  on my dual 
> 2.7 GHz PowerMac and our quad 2.5 GHz PowerMac:
> 
> 2.5 GHz G5 (gromacs.org, v-3.2.1):            15309 ps/day
> 2.7 GHz G5 (my dual 2.7,compiled w/ gcc-3.3, v-3.3):    15451 ps/day
> 2.7 GHz G5 (my dual 2.7,precompiled, v-3.3):        13492 ps/day
> 2.5 GHz G5 (my quad 2.5,compiled w/ gcc-3.3, v-3.3):     7516 ps/day
> 2.5 GHz G5 (my quad 2.5,precompiled, v-3.3):         6475 ps/day
> 2.5 GHz G5 x 4 (my quad 2.5,compiled w/ gcc-3.3, v-3.3):28800 ps/day
> 
> As you can see the Quad is not doing well with the GROMACS code.  I  
> have tried the benchmark tool XBench and my own very simple C code  but 
> have not reproduced these problems.  Any insights or suggestion  would 
> be greatly appreciated.
> 
Check the log file to see whether it uses the Altivec code. Do also 
check that you have turned off the nice feature: mdrun -nice 0 otherwise 
your job will run at ow priority.



> Thank you,
> 
> Tyler
> 
> 
> 
>  ________________________________________________________________
> (_    Tyler Luchko                           Ph.D. Candidate    _)
>  _)   Department of Physics            University of Alberta   (_
> (_    Edmonton, Alberta, Canada                                 _)
>  _)   780-492-1063                       tluchko at ualberta.ca   (_
> (________________________________________________________________)
> 
> 
> 
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-- 
David.
________________________________________________________________________
David van der Spoel, PhD, Assoc. Prof., Molecular Biophysics group,
Dept. of Cell and Molecular Biology, Uppsala University.
Husargatan 3, Box 596,  	75124 Uppsala, Sweden
phone:	46 18 471 4205		fax: 46 18 511 755
spoel at xray.bmc.uu.se	spoel at gromacs.org   http://xray.bmc.uu.se/~spoel
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