Macs basically kept pace, pretty nose-to-nose, with the Mhz speed of Intel CPUs until the Pentium II era. Apple actually beat them to about 350mhz on the 604e

Macs basically kept pace, pretty nose-to-nose, with the Mhz speed of Intel CPUs until the Pentium II era. Apple actually beat them to about 350mhz on the 604e for a year or so, whilst the fastest Pentium Pro of the time was about 200mhz. This was quite a stretch of time (92->97?). What happened after that, though, was that Intel hit the afterburners, and rocketed up to about 800mhz, and PPC got left in the dust. There was a huge 500mhz speed bump that the G3 and G4 both stalled at for a few years, and by the time they got over that, the pentium 4 was coming out, which started another jump from the P3's 1.5ghz, pushing the P4 up to about 3.5ghz. The G3 and G4 were much faster than either the 603 or P2/P3 and especially the P4, per mhz, so the launch day ad campaign saying the iMac's 233mhz CPU was "twice as fast" as the 250mhz pentiums that were out at the same time was true - it just didn't stay true once 500 mhz P2 machines came out less than a year later. It's notable that intel was so focused on the marketability of that metric that the later pentium series were worse per clock than their predecessors - a P4 had to actually be several hundred mhz faster than a P3 to be the same speed. Intel was primarily doing this to fight AMD, and it got bad enough that AMD actually had to introduce a new marketing term to indicate how fast their chips were compared to the mhz ratings of P4s. Intel completely reversed course on this with the core series - modern "core" chips like the i5 and i7 are several times faster than P4s running at the same clock speed. Far better heat/power consumption specs, too.