The processor is the heart of any computer. Most processor marketing today, is focused mainly on clock speed rather than the internals of the CPU itself. After all, to Joe consumer why get a 900mhz when you can get a 1.2ghz regardless of brand? While clock speed has always been a mater of importance, CPU's didn't progress in direct relation to it.

The first processor that was used in the original IBM PC was called the 8088. Unsurprisingly, processor giant Intel manufactured it. The processor was classified as being 16bit, and it spoke to the data bus at 8bits. This efficiently kept production costs down, as well as keep the capabilities in line with the support chips. The chip itself was far from a powerhouse. In order to display a string of text to the screen, it had to send each characters one at a time. Because of this there was an idle state every time data was sent. On top of that, it could only talk to one megabyte of memory total, and only 64k at a time (due to the offset is limited to 16 bits).

The 80286s were developed to combat the popularity of cloning the IBM PC. The 286 used 16bit connections on the motherboard to increasing efficiency. This caused the same-clocked CPU to have four times the throughput. To increase the benefits of a 286, 24 more memory address lines were added, allowing for 16Mb of physical memory.

Compaq was the first to use the 80386DX. This processor used 32 bits between itself and memory, but then dropped down to 16 towards the data bus. This led to a great speed problem. Because the data bus still ran at 8mhz, it is both the busiest and slowest part of the system. This caused many opportunities to waste processing cycles.

Next >>

<< Previous