Previously I had: A64 3800+ ASUS A8N mobo 2x1GB Gskill RAM (DDR1) I now have: AX2 6400+ dual core black box (and a new Xigmatek heatsink to go with it) ASUS M2N32 mobo 2x2GB Gskill RAM (DDR2 800) And a larger case with 3x120mm case fans and generally better airflow I kept my Audigy 2 ZS, my 6800 Ultra 512MB, my 500W power supply and my harddrives (74GB Raptor, 160GB Seagate). I'm running XP 32bit. Generally speaking I'm happy with the upgrade, I boot much faster and all my apps run much faster as well. The problem is Counter Strike Source. My old machine ran it perfectly with all the settings maxed. The new machine runs it quite well too except for the fact that it has picked up a bizarre tendency to skip around. Skips tend to happen mostly when a flashbang or nade blows up or when a player pops onto my screen, but it will occasionally happen elsewhere too. C4 explosions also cause skips. It seems to be somewhat map dependent with the most problems occurring in Nuke and Inferno but even Crackhouse or simple Gun Game maps will give me issues every now and then. In some ways it doesn't seem network lag because my pings are consistently <30 and do not suffer when the skips occur (and I'm playing on the same set of servers as before). FPS on the other hand dips drastically when I skip, sometimes to as low as 30 from as high as 100-200 depending on where I am and what I'm looking at. Turning graphics options to low does not help. On the other hand I my machine performs quite well on the CSS stress test which is offline and I just made my own server to play with bots for a very minutes and there was no skipping. The only other game I play is warcraft 3 and it does not have any issues. I'm going to install TF2 tonight and see how it performs. I have the latest Direct X and all the latest drivers for every device. I'm running Service Pack 2 but don't have all the Windows updates yet as this is a very recent upgrade. My computer runs nice and cool, idling around 28C and peaking around 42C during extended gaming sessions. Obviously I don't know whats causing the issues or I wouldn't be posting here but I have a few thoughts regarding possibilities: *I had to upgrade my machine because I fried the last mobo. My case was small, poorly ventilated and had a faulty fan. One day I turned the power on and nothing happened. No POST no beeps. Is it possible then that I also damaged my video card in such a way that it functions but not as well as it should? Seems unlikely since CSS ran perfectly all the way up to system failure. *500W power supply...is that enough? *A friend mentioned something about my RAM possibly being out of sync. I dont know enough about computers to figure out if it is or to fix it even if I could. If no one comes up with any ideas I'll format over the weekend redo everything from scratch and see what happens.