[mvapich-discuss] Same nodes different time?

[Daniel WEI]

On Thu, Mar 27, 2014 at 5:45 PM, Tony Ladd <tladd at che.ufl.edu> wrote:

> So your performance can vary depending on what else is going on with the
> other nodes in the system


Thank you Tony. I see.

(1) But how much variance?! My results shows some very disturbing
difference, on one case, to initialize the case, it takes 37s, another 5s,
yet another 2s!!!
(2) How can I do my best, or somebody else to do their best, in order to
reduce this variance? (there is 16 cores/node, so there should be nobody
using the nodes I was calling, this seems to be guaranteed)
(3) I goal is to compare intel compiler's -O3 and -O2 difference on
building my CFD code concerning speed, but now if my performance vary even
in the same case, same hosts, how can I trust my results anymore....?






Zhigang Wei
----------------------
*University of Notre Dame*
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