Intel Pentium

The Intel Pentium was the successor to the Intel 80486 in the Intel x86 line of microprocessors. It was originally going to be named the 80586, but a name consisting of only a number could not be trademarked, which led to the switch to the new name.

Externally, it is functionally the same CPU as the 486, but includes a number of internal improvements to increase its performance:

• Two 8K byte caches, one each for code and data, so that loops processing large arrays will not empty the cache.
• The main memory bus is 64 bits wide, double that of the 486.
• Branch prediction logic was added.
• Two separate integer processing units ('U-pipe' and 'V-pipe') make it a superscalar CPU, capable of executing two instructions per clock tick.
• Improvements in the numeric co-processor made it 5 times faster than that of the 486.

The memory management unit was upgraded to support 4 Mbyte pages as well as the 4Kbyte pages of the earlier machines. In addition, parity was added to the address bus.