I was given a Dell power edge 2600 sever due to my company upgrading their equipment. I have xp installed, put in a 256mb ATI video card,USB 2.0 card and it and seems to be running good so far. My question is it has 1 PCI slot and I think 6 PCI-X slots, what is the difference between the 2 and what else can I do to upgarde the machine or am I wasting my time/Money on it.