[Beowulf] Recent comparisons of 1600 MHz external Harpertown vs.235x AMD processors?

[Tom Elken]

________________________________

	From: Jan Heichler [mailto:jan.heichler at gmx.net] 

AMD Barcelona,  Opteron 2356, dual-socket, 2.3 GHz:
http://www.spec.org/omp/results/res2008q2/omp2001-20080325-00291.html 
SPECompMbase2001 = 17598

Intel Harpertown, Intel Xeon E5440, dual-socket, 2.83 GHz:
http://www.spec.org/omp/results/res2008q2/omp2001-20080325-00292.html
SPECompMbase2001 = 14789

TE>  -- I seem to recall that AMD had a
TE> rationale of choosing similarly power-consuming CPUs, but I could be
TE> wrong there.  	

> But the Harpertown that the benchmark ran on was not one with FSB1600.
And this is/could be a real difference here > since it affects the
memory performance.

You are right, Jan.  I checked that the Supermicro motherboard supported
the 1600 MHz FSB, but not the CPU.
E5462 (2.8 GHz( and E5472 (3.0 GHz) are processors that have the 1600
Mhz FSB and seem to have the same power specs as the E5440 (80W).   The
additional FSB speed would certainly make a difference in OMP2001
performance, esp. on memory bandwidth-sensitive codes like swim and
mgrid.

Here are some measurements I just made on OpenMP STREAM:
                                         8-thread
                                       STREAM Copy (GB/s)
Harpertown -                           ----------------
Xeon 5410, 2.33 GHz, 1333 MHz FSB:           6.2
Xeon 5472, 3.0  GHz, 1600 MHz FSB:           7.3
Barcelona -
Opteron 2352, 2.1 GHz:                      15.7
 (the 3 other STREAM components were pretty similar to Copy)

These were on 2-socket, 8-core systems.  Just a quick test, so not
necessarily optimal.  But Intel and PathScale compilers got the same
OpenMP stream performance on the Xeon processors with high optimization,
so that seems like a sign that the executables were pretty good.

-Tom	
	
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	Cheers,

	Jan