CPU This is the heart of your computer; the Central Processing Unit - the chip that handles most of the work. What programs you can run, and how fast you can run them depends mostly on what chip you have. Modern chips get very hot (someone once fried an egg on his for a joke) and need large cooling fans right on top of them. Remember that your chip and motherboard are very closely matched, and it is very likely that you will have problems if you change the chip for a different make. In fact you will may not even be able to get your new chip into the slot