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[Klaus Thoeni <question244277@xxxxxxxxxxxxxxxxxxxxx>]

Question #244277 on Yade changed:
https://answers.launchpad.net/yade/+question/244277

Klaus Thoeni posted a new comment:
Hi guys,

below some interesting stats from our server [2]. So far we tested 1
core on several grid nodes. The results show that the Intel cpus are
much faster than the AMD Opterons.

@ Matthias: I guess this is related to your point 2 of suboptimal
compilation. Is there a way of compiling yade with the Portland compiler
pgcc/pgc+ (see my question [1])?

Another interesting observation is that the first run is always much
slower than the subsequent one. Well, this is very strange. Maybe
something is cached?

I might do some more testing next week but it seems I we found one
reason.

Cheers
Klaus

[1] https://answers.launchpad.net/yade/+question/244322

[2] Some statistics:

For comparison I ran the exact same command on the unix prompt on 
three different grid nodes:

- 1 core on a heavily loaded opteron grid node
Job summary:
All jobs finished, total time 00:02:20 Log files: uniax.py.isoPrestress=-20e6.log Bye.

- 1 core on a moderate opteron grid node
Job summary:
All jobs finished, total time 00:01:10 Log files: uniax.py.isoPrestress=-20e6.log Bye.

- 1 core on an empty opteron grid node
Job summary:
All jobs finished, total time 00:01:13 Log files: uniax.py.isoPrestress=-20e6.log Bye.
I reran it again with 1 core on the heavily loaded node and it has a completely different time:
Job summary:
All jobs finished, total time 00:01:03 Log files: uniax.py.isoPrestress=-20e6.log Bye.
Running it for a third and fourth time on the heavily loaded node matches the above time.

- 1core on an unloaded intel cpu machine twice
Job summary:
log All jobs finished, total time 00:00:31 Log files: uniax.py.isoPrestress=-20e6.log Bye.
Job summary:
All jobs finished, total time 00:00:23 Log files: uniax.py.isoPrestress=-20e6.log

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