Thanks for making me aware of this CPU stuff, Seb. It helps to clarify a lot.
I guess overclocking is the best way to go if someone has a lower-clocked CPU like myself. That said, it's fairly inexplicable that the game would have such increasing CPU needs as the game goes on. I can't say I know of any other games that have that issue, but I'll have to keep an eye out now. Definitely seems to be an optimisation issue.
In regards to measuring GPU usage, it's worth noting that they tend to have 2 engines: 3D and 2D. Therefore some tools such as Process Explorer will often show 50% as max usage in 3D games because that's all the game uses.
The reason it will occasionally go over 50% to 100% in COH2 is that particle effects seem to be mostly or entirely rendered by the 2D engine. So 50% 3D engine + 50% 2D engine = 100% usage.
However, I think the 2D engine is probably not meant to handle particularly intensive stuff. It's possibly oriented more at basic applications? Whatever the reason, the 2D engine on my GTX770 can't handle particle effects like smoke and fire in this game.
