The idea that PPC was faster than x86 back in the PPC mac days is Apple hyperbole. There were a few occasions where the fastest PPC was faster than the fastest x86 available but they were far and few between and very slim. If all you looked at were the very carefully selected/tuned apple benchmarks you can be forgiven for thinking that (the photoshop filter benchmark using altivec comes to mind) there was a huge PPC advantage.
Here is a random google search for spec performance over time of assorted CPU arches.
The only obvious case in that graph where PPC>x86 is in mid 1995.
I can't find the one I saw a couple years ago detailing the core/clockrate comparisons of PPC's shipped in Macs with common PCs, that was much easier to read and far more obvious.
It wasn't just Apple hyperbole, PowerPC really did beat Intel at quite a few instances, and generally kept up until about 2004. AltiVec with photoshop was not just a tuned benchmark but a significant advantage on a common scenario. The Power chips also consumed significantly less power, enabling Apple to put far more powerful CPU's in laptops.
Here is a random google search for spec performance over time of assorted CPU arches.
http://preshing.com/20120208/a-look-back-at-single-threaded-...
The only obvious case in that graph where PPC>x86 is in mid 1995.
I can't find the one I saw a couple years ago detailing the core/clockrate comparisons of PPC's shipped in Macs with common PCs, that was much easier to read and far more obvious.