it had an enlarged instruction set. It is also the minimum CPU for running windows. It came in two types the 386 SX and the 386 DX. The SX had a 32-bit internal data path but it only had a 16-bit path between the CPU and the computer memory. The DX on the other hand had a 32-bit data bus between the CPU and the memory chips allowing larger data transfers so it had faster through put. It also was able to use external cache memory, usually about 64k, which also improved performance. The 386 came in two different types they both had a internal bus width of 32 bit, the SX had a address bus width of 24 bit, and a external bus width of 16 bit, its internal and external speed was between 16MHz – 33MHz. The DX however had an address and external bus width of 32 bit, its internal and external speed was between 33MHz–40MHz. 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 the instruction from the buffer area. This type of CPU has a specially designed high performance Floating Point Unit and a 16 bit internal cache. The Pentium CPUs have a bus width of 2x32-bit internal, 32-bit address, and 64-bit external, with an external speed of between 33MHz – 83MHz, and an internal speed of between 63MHz – 233MHz. 2. The term RAM stands for random access memory which is a storage device made up of silicon chips. A computer has two types of RAM these use arrays of transistor switches to store the binary data or in other words the switches on the chips can change, which is done by an electrical current being passed through them. This type of memory is volatile which means that any information that is in it when the computer is switched off is then lost, apart from the program which is being run at that time which is unaffected as it is only a copy of it. This then means that the users created data has to be saved before the computer is switched off. The term ROM stands for read only memory that can only be read but cannot be written to. This type of memory is not volatile this means that all the switches on the silicon chips are already set, which means that any information that is in it when the computer is switched

Some topics in this essay:
Pentium CPUs, Access Speed, DX SX, Instruction Register, Cycle Processor’s, RAM ROM, Data Bus, Computer Architecture, Pentium CPU, Windows CPU, address bus, data bus, execute cycle, bus width, fetch cycle, current instruction, memory address, program counter, internal speed, external speed, external external speed, bus width 32, multiple cycle processor, width 32 bit, data data bus,