[Beowulf] RASM : random memory latency test

Greg Lindahl lindahl at pathscale.com
Mon Jul 4 13:40:52 PDT 2005

On Mon, Jul 04, 2005 at 09:04:20PM +0200, Vincent Diepeveen wrote:

> Latencies are NOT dependant upon memory frequency, just dependant upon the
> speed the RAM works at (which sometimes IS related to cpu frequency in case
> of opteron as the faster opterons allow 400Mhz ram.

This is simply wrong -- on the Opteron, if you hold the memory
frequency constant, the memory bandwidth and latency improve by a
modest amount as you increase the CPU clock.

This test does have the advantage that it uses all the cpus, which is
more realistic than using just one.

-- greg

More information about the Beowulf mailing list