[mvapich-discuss] mvapich 1 vs. mvapich 2 performance

[wei huang]

Hi Noam,

We have incorperated a patch in mvapich2-1.2rc1, and it's bandwidth should
increase. You can update from our trunk and try again.

Regarding the performance compared with mvapich, there is small gap in
small and medium bandwidth achieved due to the internal architecture and
features like message coalescing. However, we believe these differences
should be hardly visible at application level.

And for large message bandwidth, mvapich2-1.0.3, mvapich2-1.2rc1 and
mvapich1 should show exactly the same bandwidth. This is consistent across
all of our testing platforms.

Thanks.

Regards,
Wei Huang

774 Dreese Lab, 2015 Neil Ave,
Dept. of Computer Science and Engineering
Ohio State University
OH 43210
Tel: (614)292-8501


On Thu, 17 Jul 2008, Noam Bernstein wrote:

>
> On Jul 17, 2008, at 1:58 PM, wei huang wrote:
>
> > Hi Noam,
> >
> > It seems that the pdf file you attached plots a different set of
> > data than
> > the numbers you posted. Could you verify that? (There is a dip
> > between 10k
> > to 100k in the figure, but i cannot see the same in the numbers).
>
> The graph shows results without CPU affinity for mvapich2 1.0.1
> and mvapich2 1.2RC1.
>
> >
> > Also, are these trends constant throughout multiple runs?
>
> Trends, yes.  mvapich 1.0.3 is somewhat faster and more consistent than
> mvapich2 1.0.1 or 1.2RC1.
>
> I've attached a new graph, with a second run of mvapich2 1.2RC1 (so you
> can see the variability), and a tar file of all the data.
>
> 												Noam
>
>