With HL2 being released I recently bought 1gb of Corsair XMS 2-3-3-6 DDR400 ram to replace a gig of Crucial DDR333. Didn't see a huge increase in performance whatsoever, both in real world and in Aquamark3. So out of curiosity I threw in all 4 sticks into the motherboard's ram slots. I was wide-eyed when WinXP SP2 seemed to load up faster than a fresh OS install with no service packs included. Things like Windows Media Encoder which was a drag when switching settings around was flying by as fast as Vdub. Firefox also loaded extremely fast when first opened. So yes there is a noticeable difference after 1GB and if you knew already shame on you for not sharing! And for overclockers I'm running all 4 sticks at a 5:4 ratio with 2.5-3-3-6 timings (2.8C @ 3.4). No crashes yet.