The "PR" Means Performance
The high-performance you get with Cyrix processors doesn’t come from megahertz alone — it comes from a superior architectural design. That’s why the megahertz (MHz) speed doesn’t tell the whole performance story.

Cyrix uses a performance rating (P-Rating) to categorize our processors. The P-Rating (e.g., PR233) gives you the performance class of a Cyrix processor compared to a Pentium processor. With the Cyrix P-Rating, you know you’re getting the performance you want — and the test results prove it.

So check the Cyrix P-Rating. You can be sure you’re getting the highest performance in the Cyrix processor class you choose.

Source: Cyrix Corporation. Configuration: M-Tech R534G motherboard; SiS 5571 chipset; Quantum Fireball ST32A011 disk drive; STB Nitro 3-D PCI graphics card w/ 4MB VRAM (driver rel. 1.50E); 1024 x 768 resolution (256 colors at 75Hz); 32MB EDO RAM; 512K pipeline burst; 33MHz PCI bus speed. All systems tested using identical configurations with one exception: the Pentium® II 233 MHz processor was tested with an M-Tech R653 motherboard and Triton 440FX chipset.