Yeah - here's a perfect example:
My GAMING RIG (2.8 Ghz AMD FX-62): 31.468 seconds
My TABLET PC (2.0 Ghz Intel Core2D): 26.015 seconds
The AMD is, spec-wise, 40% faster and yet, performance-wise, it's 20% slower.
The FX series was originally cheap and faster than anything when I got it. Since then, Intel has completely trumped them. I just don't plan on upgrading anytime soon because a) I'd need a new motherboard and b) this processor is still plenty fast enough that I can wait for Intel prices to come down, or for AMD to do something spectacular (yeah, right.)