[Pw_forum] Seeking Advice on Small Hardware Platforms for PWscf Implementation

[Alexander Shaposhnikov]

On Thursday 22 November 2007 11:13, Axel Kohlmeyer wrote:

> PG> On the other hand, one could consider building a small MPI-connected
> cluster PG> for about the same amount of money.
>
> i don't think it would be worth it. you can only afford gigabit
> ethernet and i'd rather go for a dual cpu "server board" than for
> two desktop boards. the dual-quad will give you more flexibility
> (you can run a big serial and up to 8 mpi threads). particularly,
> for development, this is a desirable setup. in production, things
> are different...
>

I want to comment on this one, 
for the small budget dual Xeon paltform is just  a waste of money as 
performance will be inadequate. 
Going for the small 2-node quad-core cluster instead can give upto 100% faster 
exec times in pw.x  and upto 150% faster for cp.x/cpmd.x.

From my experience with dual quad-core Xeon machine, cp/cpmd codes scale very 
poorly, mostly less than 3x on 8 cores, and pw.x code scales 4x-4.5x on 
average. My home desktop machine with Intel C2Q at 3.6GHz (4 cores) is as 
fast as dual Xeon X5355 2.66Ghz (8 cores) in pw.x and 10-20% faster in 
cp.x/cpmd.x.

Just my 2 cents.