Hey everyone. I have an XPS 400 that I got from the junkyard and have made it my own upgrading it with parts I've either found or bought. It's come out to be a good computer but I need more RAM. I have four 512mb sticks in it but I need it to be a bit quicker. The only problem, I'm not so sure about what motherboard is in it. I used Belarc and it told me it was a Dell FJ030 motherboard. But I'm not too educated on Motherboard-RAM compatibility. According to this - http://www.ascendtech.us/dell-fj030-dimension-9150-motherboard_i_mbdeldimen9150.aspx - it will take up to "DDR2 Up to 4 GB DUAL Channel" but I don't know what the DUAL Channel means. And also, I don't know if it has a MHz cap. So can anyone with some experience tell me how I can upgrade my RAM and what kind and such? Thanks!