I've screwed up a bit with my new rig. I bought 512MB of Crucial PC3200 RAM with a mobo and CPU from Komplett. Now that worked fine, I had no problems. Then, I decided to buy another 512MB of the same RAM, with the same manufacturere code, but from Dabs. When it arrived, the box was identical to that of the first RAM. However, when I took it out of the box, I noticed that it was double sided, whereas the 1st lot of RAM I got was single sided. I was a bit suspicious but I tried to run them on the same channel, and lo and behold my system wouldn't boot. So at present, I've got them on different channels, so I still have the full 1GB but it's only single not dual channel. What has happened here? Who has sent the wrong RAM? Or should I have bought it from the same supplier? Also, what kind of speed increase would I get from running dual channel. Eventually, I will want 2GB of RAM, will I be able to use 2 double sided on one channel and 2 single sided on the other channel? EDIT: Also, I my system has completely frozen twice since installing the new RAM in a different channel, and I hadn't had a single problem when just using the first RAM that I got.