Im kinda confused about something. I have an Asus P4S800-X motherboard. It says it has a SiS 655FX Chipset. I havent even heard of that until I looked it up. I read that Pentium 4s run on 775 chipsets. So ***? If I buy a 775 chipset motherboard, will my pentium 4 work with it? Cause I dont wanna waste my money. I want a motherboard supporting DDR2 and PCIe. ANd my Pentium 4. Any help?

775 is a socket distinction not a chipset. It is the most recent Intel socket for P4 and Core Duo's. There are 775 pins in the socket.

From a brief search your motherboard has a Socket 478. There are also P4's for socket 478 but you cannot use a Socket 478 P4 in a Socket 775 motherboard.