Introduction & History

The processor company formally known as Cyrix is well known to many computer users due to their past line of poor processors. Cyrix fist started out in March 1992 when Cyrix released the Cyrix Cx486SLC line of processors. The Cx486SLC was one of the first Intel i386 alternative processors on the market. This CPU was available in clock speeds ranging from 20Mhz up to 66Mhz using a FSB of 16MHz all the way up to 33Mhz. The processor itself contained 600,000 transistors and had 1Kb of L1 cache and 128Kbyte of L2 cache provided on the motherboard. This processor was used on motherboards that used 386 processors and had no FPU.

The next CPU from Cyrix was the Cx486SX. This CPU was released on May 1993. The processor itself used the same 600,000 transistors as the SLC processor line, however, this CPU increased the L1 cache form 1Kbyte to 2Kbyte and allowed for up to 512K L2 cache on the motherboard. Clock speeds had changed ranging from 33Mhz up to 50Mhz using the 33Mhz to 50Mhz range FSB, this CPU was an alternative to the Intel 486 and AMD 468 CPU but still contained no FPU.

The next jump up was to the Cx486DX range of CPUs in September 1993. The new DX line of processor used a 1.1 million transistor layout, ranged in speeds from 33Mhz up to 100Mhz and increased the size of the L1 cache from 2Kbyte to 8Kbyte. Again, this CPU was an alternative to AMD and Intel 486 DX line of CPU’s.

For the next 2 years, Cyrix didn’t release any new CPU’s until in October 1995 when Cyrix released the Cyrix 5x86 processor. This processor had a total transistor count of 2 million on a 0.65-micron die. The clock range of this CPU was from 100Mhz up to 120Mhz.

With the 5x86 CPU being a disaster in the first month of sale in the retail market, Cyrix went back to the drawing board and came out with the Cyrix 6x86 Processor. The 6x86 processor featured a 3 million-transistor count on a 0.35-micron die. The speed range of this CPU was from 80Mhz up to 150Mhz (PR90 to PR200) with a FSB range from 40Mhz up to 75Mhz. During its initial stages the 6x86 processor was a huge hit as its raw performance in business applications was better than any Intel or AMD processor. However when the 3D gaming craze evolved, the Cyrix 6x86 processor suffered very badly because of its very weak FPU performance, even the PR200 CPU would run slower in Quake 1 than a Pentium 90. The Cyrix 6x86 CPU supported 16Kbyte L1 cache and up to 2MB on L2 cache.

February 1997 saw Cyrix enter the mobile PC market with the introduction of a new processor called the Cyrix Media Gxi processor. The Gxi processor included 2.4million transistors on a 0.30 micron die. Clock speeds ranged from 120Mhz up to 180Mhz. The reason this chip was so good for notebooks, was that not only was the Gxi a CPU, it also contained a graphics engine and an audio engine, making this the first integrated CPU. The video engine was Cyrix’s own designed based on the S3 Virge video technology with support for up to 2MB of memory provided on the motherboard, the audio engine was based on Eagles ESS688 Audio processor.