s width of 32 bit, its internal and external speed was between 33MHz40MHz.The 486 were the next CPU, this is still produced, there was little change to the 386 instruction set, but the 486 ran at speeds between 20MHz to 100MHz. There was more emphasis placed on the enhancements to improve the performance. It was also available in the DX and SX varieties. The difference between them was that the DX had a maths co-processor the SX did not, the Motherboards that used the 486SX chip had a spare maths co-processor socket to upgrade to a DX. The 486 chip because of its design to carry out the most common instructions in a single clock cycle this was a faster than the previous CPUs. It also had 8k of bit in cache memory, the new burst mode it had, allowed memory transfers from consecutive memory locations to be carried out at one clock cycle. The 486 came in four different types they all had a bus width of 32 bit (internal, address, and external), with an external speed of between 20MHz 50MHz. The differences between them were in the internal speeds of the CPU. The SX had an internal speed of between 20MHz 50MHz, the DX had an internal speed of between 25MHz 50MHz, the DX2 had an internal speed of between 50MHz 66MHz. The DX4 had an internal speed of between 100MHz 120MHz, which was actually faster than the bottom of the Pentium range. The Pentium CPU came and is the current entry level standard for computers. This CPU is effectively two that are in the one chip. This then allows two instructions to be executed in parallel, which means it greatly speeds up throughput. It also has the main mathematical operations hard wired into the chip this then means that it can be up to ten times faster than the 486DX maths coprocessor can. All the Pentium models are supercalar. The basic chip has two integer processing pipelines. It also has a branch prediction facility which is 90% of the time correctly predicts the flow of the program and fetches th...
