dgingeri

Distinguished
I found something weird last night in World of Warcraft.

I noticed that my cpu wasn't getting up to 35% utilization while I was playing WoW while overclocked, so I decided to test out how it performed under various circumstances. Since WoW is about the most intensive thing I regularly run these days, I figured saving a bit on power would be a good thing. Well, it ran just as well at standard clock rates, but it is kind of a weird thing. This is what I found:

Tested in a crowded Dalaran, since that is the most cpu intensive situation. people go in and out, so things can vary. I tested it for half an hour at each setting, so I would have a decent sample.

4.2Ghz with HT on: 60-65fps
4.2Ghz with HT off: 65-70fps
2.66Ghz with HT on: 65-70fps
2.66Ghz with HT off: 55-60fps

At the faster clock rate, HT was a hindrance, but at the lower clock rate it was a help. What do you guys think is going on?
 

dgingeri

Distinguished
I think I figured it out. It seems WoW only uses 4 threads, and those sometimes get assigned to both logical cores on the same physical core. I have taken measures to make sure WoW will only be used on cores 1, 3, 5, and 7 now.