MAC processor use PowerPC CPU. These use a completly different instruction set, they are not compatible with x86 Intel/AMD instructions.
Performance of PowerPC CPU are very impressive, these chips are running at low speed but are very efficient. You can't compare MAC vs PC. MAC are very good for multimedia stuff because Apple applications in this domain are very mature and stable.
There is not MAC vs PC. You can't compare mass market products with more specialized products. Both MAC and PC are good and excel in their respective markets.
Lookin' to fill that <font color=blue>GOD</font color=blue> shape hole!
Compare? Simple. Take Photoshop on a Mac, take Photoshop on a PC, run the same filter. See which is faster. Of course you'll use other applications as well (whichever matters to you). If the software you want is only available for Windows or MacOS (like Final Cut or 90% of the games out there), then really, it's not even a choice anymore now is it?
"We are Microsoft, resistance is futile." - Bill Gates, 2015.