[Wien] Relative importance of Bus speed + Cache for Wien2k

[Laurence Marks]

I am talking with a vendor about a probably cluster purchase. For a
comparatively small change in total cost I could either go with Option
1 (below) which has a faster bus and cpu speed but is dual-core and
only has 4MB cache, or a quad-core with 8MB cache but a slower bus.
Has anyone any information about how bus speed effects Wien2k
particularly when using mpi? My suspicion is that it is a
comparitively weak term with the recent mpi improvements, and
multithreading or running 4 tasks on the quad-core versus 2 on the
dual-core is more important, but I may be wrong.

Does anyone have comments on the relative importance of bus speed
versus cache for WIen2k?

Option 1:
Intel Xeon Dual-Core 3085 3.00GHz 1333MHz FSB w/ 4MB Cache
Motherboard will go up to 1666MHz FSB

Option 2:	
Intel Xeon Quad-Core X3230 2.66GHz 1066MHz w/ 8MB Cache
Motherboard will go up to 1066MHz FSB

-- 
Laurence Marks
Department of Materials Science and Engineering
MSE Rm 2036 Cook Hall
2220 N Campus Drive
Northwestern University
Evanston, IL 60208, USA
Tel: (847) 491-3996 Fax: (847) 491-7820
email: L-marks at northwestern dot edu
Web: www.numis.northwestern.edu
Commission on Electron Diffraction of IUCR
www.numis.northwestern.edu/IUCR_CED