Poor performance in a patch but benchmarks ok?

We were having performance issues with an installation, which were solved by turning off Spread spectrum in the Bios, I remember coming across this years ago, but haven’t seen it more recently, its now on my list to check everytime!
so for your information, if your not aware of this, patch went from 20fps to 4-50fps

http://forums.techguy.org/4938540-post10.html

whoa! why isn’t it off by default?