QUOTE(whentech @ Dec 6 2005, 11:20 AM)I have read on the Microsoft website that only Windows 2003 Enterprise and Datacenter Editions support Non-Uniform Memory Access (NUMA). Does this mean that I need (or should) purchase Enterprise Edition (as opposed to Standard) when using a Dual-Core Opteron processor such as the 275 or 280?
Though far from an expert, my understanding is that XP Pro and WIN XP64 both support NUMA, provided the motherboard and Bios are set up correctly and that the PAE is enabled (automatic during install). With a dual Opteron setup that is the only way to access memory that is split between the two processors.
On my system: 2 x 250 Opteron with 2 x 1GB ram per processor. The PAE switch is set automatically by XP install and 3 GB of memory is available to windows (the other GB disappears into the PCI never-never-land with SP2 but that's another story).