First of all, you should not compare the performance of vanilla CoH against EF, because it is obvious the former will run perfect. Why? because the game was made to run fine with the four original factions. Then why EF sometimes lags? because it is a mod that adds a lot of new things, which the engine is not optimized to handle.
Thanks to DMz and Beefy^ we got a better performance now than in the past releases, but that only applies to PvP games and short skirmishes because as long as the AI push a lot of stuff, the resources needed to play are dramatically increased. So, if you don't want to have laggy games with EF, I have some advices:
- Never play the infinite/unlimited pop cap mode.
- Avoid very detailed maps, specially if they are 3v3 or 4v4.
- Do not set shaders in "Ultra" in the graphics settings.
- Playing Annihilation vs AI is not a good idea either, because most of the time those matches are long and tons of objects are created, draining a lot of resources.
If you combine Annihilation with unlimited pop cap mode, that spells doom so, avoid it as well.
Also, do not report your own post to get more attention. We read all the topics everyone posts, and that won't help you to get a faster answer.