David Hart wrote: > Because the memory controller resides on the CPU in > Opteron systems, all 8 CPUs must be populated, but > this can be achieved with the slowest/cheapest model, > the Opteron 840 (1.4 GHz).
I would second using the cheapest CPU part available, which currently is the 1.6GHz part, you'll save pocket change by going with the 1.4GHz part (for the 2xx series, the difference is about $10). The low clock speed is deceptive. If you use one of the AMD64 optimized compilers (e.g. http://www.pathscale.com) rather than GCC, the real performance is stunning even on "slow" CPU parts -- it is as fast or faster than pretty much anything else in the general case. For SMP codes, the only thing comparable is the Unix Big Iron (e.g. IBM's Power series boxen) in terms of how it scales across multiple processors. Of all the different architectures I touch, the Opteron is my favorite. Top-notch Big Iron performance at commodity prices. Itanium is a bit better for floating point (PPC970 only for DSP codes), but not much and it is worse at a lot of other codes and expensive. It is worth noting that the Intel AMD64-compatible chips will be ISA compatible, but missing all the features that make the Opterons scalable. And as Brian noted, it has an aggressive looking roadmap. There is a new version of HyperTransport coming out relatively soon (maybe first part of next year?) which will increase the scalability even more, and the multi-core CPUs should be with us shortly. As the big server vendors put more and more money into big Opteron boxes, Linux being the default OS, this looks like the bang/buck champion for the foreseeable future. 64-bit Windows may be viable, but I have no idea if it will run well on the bigger systems as a practical matter. The Windows VM continues to be funky from what I understand, though I have no personal experience. j. andrew rogers ------- To unsubscribe, change your address, or temporarily deactivate your subscription, please go to http://v2.listbox.com/member/[EMAIL PROTECTED]
