I want to buy an old PPC mac, I found a PPC 6500 (603e cpu) running at 250 Mhz and a PPC 7600 (604 cpu) running at 132Mhz. I know that the 604 cpu is better than 603 line, but wich of those systems is faster? And what does a 603e 250Mhz cpu equals to an intel cpu?

The 6500 will kick the 7600's ass. The 7600 is much more cheaply upgradeable to a G3 or G4 if that's your cup of tea, though. p

Do you know of a site that compares mac cpu to another, that kind of stuff meanwhile i'll take a look on tha web...

Unless the clock speeds are similar, the comparison of one Mac CPU to another isn't particularly valid at *any* level. Why not? I could write a small thesis on why not, but the short of it is that the differences are minimal enough that well-written, general-purpose code will be basically identical in speed on *any* CPU at a given clock rate*. If you're going to be doing a lot of specialty stuff (heavy FPU, Altivec-optimised code, that sort of thing), then I'd say something like a 604 or G4, respectively, would be "better" at maybe as little as 1/2 to 2/3 the clock speed of a similar 603 or G3, respectively. * The major exception I can think of is the transition from the 68030 to the 68040, where even the FPU-less 68040 will make a faster FPU-equipped 68030 system eat its dust. p