Originally posted by: lederhosen
The number corresponds directly to the Intel's GHz. For example, an AMD 3200+ performs equal or better than an Intel 3.0 GHz processor.
Depends on the 3200+ and the Pentium 4 that you are talking about.
An Athlon XP Barton 3200+ was closer in perfvormance to a 2.8-3.0GHz Northwood P4 with HT than it was a Northwood 3.2 GHz. Since the Prescott core is less efficent per clock than the Northwood, especially at lower clock speeds, a gap between a Barton 3200+ and a 3.2E will be smaller. But then again, the new 640 model LGA775 P4 has 2MB of cache, so in some apps the extra cache the bring the 640 back up into Northwood performance territory. But when you factor in the fact that the larger cache on the 600 series P4s is slower than the smaller cache of the 500 and E series Prescotts, you can find a lot of situations where it hurts you to have the newer chip with more cache. Also, none of these various 3.2 GHz P4 chips will be quite as fast as a Athlon 64 3200+, thanks to the on-die memory controller of the A64 that makes it a formidable gaming chip, but the P4s will excel at multitasking situations thanks to their Hyperthreading technology.
And then there are the Celerons, Celeron Ds, socket-A Semprons and socket-754 Semprons and they all perform markedly different from each other at similar clock speeds and PR ratings, but in general a 3.2GHz Celeron will be quite a bit slower than a 3.2GHz P4 - just as a 3200+ Sempron is a lot slower than a A64 of the same PR.
As you see it is incredibly hard to determine the performance of a chip based on either its PR or its clock speed. You basically just have to look up some reviews and buy based on what chip at what price performs best in the particular applications you primarily use. An Intel chip might be great at running multitasked office apps, but suck at games compared to a comparibly priced AMD chip, so different chips work better for different users.