The following is according to the Cyrix Web page at http://www.cyrix.com/textonly/process/prodinfo/standard/cx-pratg.htm
Following the guidelines established by the P+ formula, the 6x86 processor achieves these ratings:
100MHz -- P120+
120MHz -- P150+
133MHz -- P166+
That is, a 6x86 at 133MHz is equivalent to a Pentium at more than 166MHz. However, the 6x86 is slower at floating-point maths, which may make it worse on CAD and 3-D graphics than a Pentium, and the Cyrix chips currently run hotter.
- Ian Yates