Cyrix

Another x86 microprocessor manufacturer. Cheaper than AMD. Another rival of Intel. Cyrix processor usually means lousy FPU performance. They also has a tendency to overheat.

You've got to give them credit. They were able to manufacture decent processors for under half the cost of "the other two". By decent I mean "decent overall performance"... they were not chips for gamers.

The used a series of smart tricks the make the chips inexpensive and fast(er). The first being the addage of a buttload of on-chip cache; they could then lower the clock while maintaining most of the performance -- this is where the PR ratings came in. The second as to have a purly emulated FPU; they used the main processor to emulate a Floating Point Unit -- lowered costs dramatically, but totally soaked the performance.

We're all happy that the Cyrix III and IV have *real* FPUs, now.

The rule of thumb was that Cyrix' processors were fantastic, pound-for-pound, when used in an office environment running Windows and Microsoft Office, but that they were inappropriate for games due to the lack of an FPU and the attendant drop in 3D performance. 'Carmageddon' running on a Pentium 120, for example, was quite playable; whereas the same game running on a '166' Cyrix 6x86 juddered and jerked.

A note about p ratings, as mentioned above by xunker - a Cyrix '166' actually ran at 133mhz, but, when used with anything that didn't require a great deal of floating-point mathematics, was roughly equivalent to a Pentium running at 166mhz.

Nonetheless, from about 1995-1997 Cyrix had a higher profile than AMD, and they kicked off the market for cheap, decent PCs. By 1999, however, competition from Intel's Celeron, and a new range of games-orientated AMD chips - not to mention the lack of development due to National Semiconductor's aforementioned insistence on 'value', and the fact that staff were leaving in droves - led to Cyrix becoming nothing more than a brand name.