Poor system perf. / Mobo drivers

HiI recnetly changed from a an XP1600 to an XP3000 and doubled the amount of RAM to 1GB (DDR, PC3100??), although performance in games such as FS is about the same. There must be some bottleneck somewhere and I'm having trouble identifying it.Would anyone be so kind as to suggest what I could do to perhaps solve the issue?Also using an ASUS A7N8X deluxe mobo - what drivers should I use? It has an Nforce chipset I do believe.Cheers