[gmx-users] Benchmarks vs memory bandwidth
mike.sullivan at alltec.com
Tue May 18 21:42:43 CEST 2004
I ran a few tests to determine the importance of memory bandwidth.
The results are rather
interesting. The test case is a 50ps simulation that was given to me by
a student. The machine
is a Dual Opteron 248 ( 2Ghz ) based on a Tyan S2885 using 1GB DDR 400
ECC Reg modules.
This was to determine if the Tyan 2875 was a viable gromacs platform.
It has only
4 dimm sockets that are attached to one of the two cpus. The second cpu
must access the
memory pool via the first. You get only two memory channels as opposed
to four on the
Suprisingly even with a single memory channel the performance is similar
full bandwidth run.
4 memory channels ( 2 dimm Per cpu ) 23:06
2 memory channels (2 on a single cpu ) 23:24
1 memory chanel ( 1 dimm on single cpu ) 23:37
FYI for the last case
NODE (s) Real (s) (%)
Time: 1417.000 1417.000 100.0
(Mnbf/s) (GFlops) (ps/NODE hour) (NODE hour/ns)
Performance: 103.784 3.102 127.029 7.872
This was using the 3.2.1 rpms and run on Suse Enterprise 8.0 for AMD64
Mike Sullivan V.P. Performance Computing
@lliance Technologies, Voice: (416) 385-3255 x 228,
18 Wynford Dr, Suite 407 Fax: (416) 385-1774
Toronto, ON, Canada, M3C-3S2 Toll Free:1-877-216-3199
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