1Ghz G4 = 2Ghz+ when it comes to processing power.
You gotta realize x86 is NOT all that good; it's slow, and unoptimized, meaning even though we have 1.7Ghz AMD CPU's and 2.xGhz Intel CPU's neither one is running at true Ghz speeds.
Also, if you did some research you'd find that Mac's have almost the same games, and same amount of games, that PC's do.
This reply is completely un-biased, as I am an AMD XP 2100+ (x86) PC user.