[Pw_forum] FFT & MPI - issues with latency

Konstantin Kudin konstantin_kudin at yahoo.com
Mon Jan 30 13:35:31 CET 2006


 Axel, Nicola, thanks for sharing the experiences!

 I am actually wondering now if the benchmarks that Nicola posted did
not have the 2nd Xeon cpu running threads with the GOTO or MKL
libraries (launched on their own). If such threads were running, then
that would make the 1 cpu per node times artifically low, making it
look like the 2nd cpu adds very little.

 As far as Axel's comments go, the idea of caching the G-space to
R-space fourier transforms sound intriguing. Perhaps going to 8 or even
16 cpus is nothing to high rollers like Axel :-) , however, for mere
mortals using the regular Gigabit and cheap clusters that would be a
step forward !

 Also, this parastation for Gigabit-not-really-Gigabit sounded like it
could reduce the latency with no new hardware. Was it implied that such
a solution was somewhat unstable? How easy is it to get it running, and
to use it afterwards?

 Kostya

__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com 



More information about the users mailing list