[Beowulf] network transfer issue to disk, old versus new hardware
Bogdan.Costescu at iwr.uni-heidelberg.de
Tue Jun 5 10:03:38 EDT 2007
On Mon, 4 Jun 2007, David Mathog wrote:
> Athcool does cut the idle temperatures of the nodes considerably,
> but apparently also prevents them from performing this sort of
> transfer at full speed, whether or not buffer is used.
Well, near the top of the athcool website there is a warning and one
the listed items is 'a slowdown in harddisk performance' - so nothing
new here ;-)
> Which is interesting because it didn't have any measurable effect on
> CPU bound processes. I had thought it would shut itself off and get
> out of the way when the CPU rate was high, but apparently not.
CPU bound and I/O bound processes use the processor in different
ways... When doing only I/O, the processor is often waiting for the
hardware, so the load on the processor is low.
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