I asked that question awhile ago. As far as athlon XPs go, the k7s5a and its varients do, just check out
http://www.ecs.com.tw and look under socket a and see what they have listed. For the memory, yes and no. Depends on the chipset thats being used. Check out sis's site,
http://www.sis.com.tw and do some searches for listed memory support. Some mobo's do, some don't. I just ran into the problem where i bought 512 of high density sdram, and couldnt quite use it. In the K7S5A that I have, when I put the stick in, it wouldnt boot. However putting another in along side it, would allow the machine to boot, but then windows xp wouldnt load. So it all boils down to what the motherboard is using for a chipset. If your still unsure, look at the mainboards memory listings on the ecs site, and also download the user manuals and it will list if it can or not! [img]smile.gif[/img]