<br>I installed the latest mpich2 with hydra and also configured the device to sockets with no change. <br>I still get no performance improvement in speed in a four-process mpich run over a single process run.<br><br>I tried some experiments:<br>
Running without mpi i immediately see a drop in speed slowing by 80% when starting a second independent run<br>I
get the same speed regardless if i run 4 copies without mpi all at once
or submit a n=4 job with mpi with my computation grid 4 times wider<br>
running one job without mpi takes as long as the same computational grid with mpi with n = 4<br>its like it is not doing true parallelization even though i can see all cpus utilized during the mpi run.<br><br>Someone else suspected I have some kind of memory bandwidth problem.<br>
I am using the Q6600 2.4 ghz processor with an Asus p5n-e sli motherboard. i have 8 gb ram<br>Could someone please help me understand if there is something about my hardware that is indeed limiting?<br>I purchased this hardware hoping I could realize the x3-4 parallelization.<br>
If it is my hardware what specifically do I need to look for in a future purchase?<br>Is anybody else running mpich2 application on a quad core chip without issues? If so what is the chip/motherboard?<br><br>Zach<br><br><br>
<div class="gmail_quote"><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
----------------------------------------------------------------------<br>
<br>
<br>
> > I am running the latest ubuntu with a Q6600 quad core cpu and the mpich2 that came with ubuntu<br>
> > I can run my parallelized code over the four cores (i see it in 'top')<br>
> > however, the speed increase over a single process is hardly improved for 2,3, or even 4 processes.<br>
> ><br>
> > i was able to run the same code on a linux cluster through my school with speed increases as expected.<br>
> > am i doing something wrong?<br>
<br>
<br></blockquote></div><br>