The CPU architecture is the number of bits in the processed the numbers written in binary notation. This technical feature of the processor is one of the most important, because it determines its performance.

Therefore, for the designers it was important to increase the bit width of the processors. In modern personal computers are 64-bit processors. But it was not always so, the first Intel microprocessors in 1970 was only 4-bit.

To make it clearer, what was going on, you need to talk a little bit about what is binary numeral system what is bit and how they relate to CPU architecture.

If you do not go into the details, the computers process information by loading the numbers in the binary system from the memory to the CPU, processing them and writing the result back to memory.

The basis of the computer industry is the binary number system. In ordinary life we are accustomed to using the decimal number system where all numbers are written with ten digits from 0 to 9. The binary number system uses for numbers only two digits: 0 and 1.

When storing in the memory each digit of the number is stored in a separate memory cell. These units of information in the binary system are called bits.

Each processor processes numbers that have a certain number of bits. Degree is the "working place" digit in the number. For example, in the usual decimal notation the digits are called tens, hundreds, thousands and so on.

The more the number of digits, the greater is the number. Each digit of the number is written in the place corresponding to its category.

Each bit of the number in binary form is used to record one digit of that number. In each cell of the RAM of the CPU is stored a single bit to store one bit of the number. It turns out that the storage of large numbers requires a large number of digits and the processor memory.

The maximum number of bits and the bit numbers, which can run the processor, called bit processor.

The bit width of the processor influences the speed of the processor with the data, because the bottleneck constraining the growth of processor speed, was the speed of data transfer between processor and memory. And the more bits have passed, these numbers more and more information is transferred at one time between the processor and memory, the higher the speed of the processor.