How do you tell which CPU fits what motherboard?

Answer 1

I am going to assume you're being technical and using the term CPU meaning the processor specifically. Usually when you buy a motherboard located somewhere in the specifications it will tell you what "socket" the motherboard supports. Just like how only US electrical plugs will fit into US electrical outlets, it is the same for motherboards. For example, the Asus Intel P965 Motherboard states it supports socket 775 processors. Usually the motherboard will have the processor it supports in the title name, this one being Asus Intel. So by buying that motherboard you would go and buy a processor, that's made by Intel, with a socket 775 fit. Unfortunately technology has its limitations, so if you buy a motherboard and your socket becomes outdated, you will probably have to buy a new motherboard to accommodate the new sockets if you ever want to upgrade the processor. On the plus side, motherboards aren't all that expensive. However, processors ARE expensive, especially if you plan to go over 2 Gigahertz in speed. The Intel Core 2 Extreme Processor E6800 2.93 GHz processor costs $1,049.99, according to Best Buy. So, make sure you plan your computer investments wisely.

Answer 2

CPU: Check socket type and wattage of it. If the motherboard is fine with both, it'll work.

RAM: Check type (ddr1/ddr2/ddr3) and make sure capacity is within the max supported by the motherboard. (RAM is also known as memory modules)

For the memory, go to www.crucial.com and use their memory upgrade scanner, that's very helpful, tells you what you've got, what you can have, and even some possible products you can use to upgrade.