[gmx-users] scaling on xeons

[David van der Spoel]

On Thu, 11 Mar 2004, Anton Feenstra wrote:

>Y U Sasidhar wrote:
>
>> I have run dppc bench mark on our dual xeon(1.8 GHz/1.4Ghz):
>> 
>> on 1.8 GHz Machine
>> 1 node = 129 ps/day
>> 2 nodes on same machine = 198 ps/day
>> scaling = 76%
>> ==============
>> 2 nodes:  1.8 GHz + 1.4 GHz  = 167 ps/day
>> scaling = 64%
>> ================


there's an option to grompp -load
that allows you to sepcify the relative speed of the machines. In your 
case
gromp -load "1.8 1.4"
should do the trick.
=
>> 
>> will I benefit if I use Gigabit switch and ethernet card ?
>> right now we use 10/100 fast ethernet switch and intel ether express pro 
>> 100B network card
>
>Your main problem will be load imablance between the 1.4G and 1.8G machines,
>so that both can never be faster than twice the speed of the slowest. There
>doesn't seem much to gain by Gb ethernet.
>
>
>

-- 
David.
________________________________________________________________________
David van der Spoel, PhD, Assist. 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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