First of all, I have a fairly decent system. AMD Phenom II X4 965 (3.4GHz), ATI Radeon 5870, 4 GB of RAM, Windows 7 64-bit, etc. I am well above both required and recommended specs. The game recommends I use "Ultra" settings.
I tried, but I'm getting unusually bad framerates, that I don't experience in any other game. I get 20-30 in single player (which seems slower than I *should*). However, the real problem is multiplayer, in 3v3 or bigger maps. I get very bad FPS, around 10-20 FPS. Once we start hitting close to 100 support each, my framerates get drastically worse. I start seeing framerates like 5 FPS, and even sometimes getting down to 1 FPS for several minutes in a row! It's unplayable like that.
I have friends who have slower CPUs, older and worse video cards, and less RAM, and the game runs perfectly smooth for them without lag. I ran benchmarks against one of my friends, and I blew him away in almost everything except his network connectivity was *slightly* better than mine, as was his hard drive access, but I still got a reasonably good score.
I tried lowering settings from Ultra to completely minimum. It didn't impact framerate at all that I could tell. If it was different, it was only by 2-3 FPS.
I tried updating my video drivers to the very newest (and then even the 10.7a Beta drivers), but no change.
I tried using Replay Mode to watch a game, to rule out network issues. It ran *slightly* better, but still very bad. I only got down to 5 FPS instead of 1 FPS with replay vs the real game that was recorded.
I checked Task Manager, and my overall CPU usage was about 30-35% when running the game. 2 CPUs were running at about 60%, while the other 2 were running around 15%. My video card was around 40 degrees C.
Now this is where it gets really weird.... Brace yourselves...
I decided to try to push my video card harder. I opened up World of Warcraft and logged in.
WoW was reporting about 120 FPS in game. SC2 was in windowed Maximized mode, as was WoW....
I tabbed from WoW to SC2 and saw something completely mind boggling....
SC2 went from 5-10 FPS when running alone, to 50-60 FPS when WoW was running in the background!
What is going on here!? How can this possibly be??? I was at a loss before that was discovered but that has blown my mind!
Why do I see a dramatic increase in performance from SC2 when WoW is running????
Below is my DXDiag info...