Hello, I just registered on this board, after learning a bit about dual channel memory from posts here. Didn't learn enough though... First off, thanks for the scoop on why dual channel doesn't work with Athlon XP. I once had it in an ASUS board that was supposed to run dual channel. I could not tell the difference in performance when it booted up in dual channel mode vs single channel. (The BIOS displayed which it thought it was running on boot-up.) I am now building up a system with a Pentium D (805) in a ECS P4M800Pro-M mobo. This is claimed to support Dual Core operation. A couple of general questions... 1) Regarding Dual Core and Dual Channel Memory operation, are they totally independent...? Will both features work together, or can you just get one or the other (or neither) on this combo...? I see NO mention of dual channel memory in the mobo manual. 2) I plan to run Win 2000 on this machine. Does that support Dual core, Dual Channel, or both. Or are these modes totally independent of the operating system software...? 3) My understanding of Dual Core operation is minimal. I guess it means you could have one core running MS Word while the other runs MS Excel, or plays a game... Is this correct? If so, is the operator in any way aware of the machine operating in this mode, or have to do anything to make it operate in the dual core mode? Or is the operator totally unaware of the dual core operation, except for, hopefully, better performance...? 4) Should I be looking to stuff the memory in this mobo with "dual channel" single-sided pair of DDR2 PC4200 dimms (533 MHZ) for best performance (the top mobo rating)? If so, is there any reason I should NOT use PC5300 (667 MHZ) dimms, for the sake of possibly overclocking, or using them in a faster mobo in th future. (I am currently using PC3200 dimms with an AMD Sempron 2800+ in a MSI mobo rated only for PC2700 memory. It is working fine...!) In general, I would guess faster memory would work in a slower system, but I don't really know that can be expected in all cases... I realize this is a lot to choke on all at once.... My apologies... and thanks a bunch...!