The Central Processing Unit is described as the brain of the computer, it handles and processes all data within the computer including performing basic algorithms, input, output and logical operations of the system. Games consoles use CPU's just like any other computer device.
The CPU processing speed all depends on the clock speed, the clock speed is how many instructions are carried out per second. You can edit the clock speed of your CPU however your computers life spam id reduced and the computer has a higher possibility of over heating.
Cache
The CPU ha sits own dedicated cache allowing for quick reading and access capability, because the CPU is so fast and can handle processors and needs data quickly if the CPU pulled the information directly from the hard drive or ram the processing would be hundreds of times slower because having its own dedicated cache is must faster.