When u open CA,
Try going Ctrl, Alt Del and go proceses, Find Engine.exe
Right click it and click Set Priority and select HIGH.
Or
Get GameBooster
Or
Get a better internet Connection
Gamebooster is...ok....
try running CCleaner
Also, what video card are you using?
1. Internet is slow.
2. theres something big running in the backround
3. Game booster usualy doesnt do that much, but it depeds on your comp.
4. open up task manager and delete some useless processes.
Theres a sticky somewhere that has a bunch of ways to reduce lag.