Here is a tip to fix CPU lag on Battlefield 4 by Redditor Rocket Potato. battlefield 4 lag fix This fix only works with Windows 7 x64 and x32 and only in systems using more than 2 physical CPUs or more than 2 logical cores. Windows 7 has a feature called “Core Parking” which turns off CPU cores when not being utilized. For many gaming applications, this can be unhelpful. There is no switch to turn off this Core Parking, so you need to edit a few registry values to force Core Parking off. For me, this boosted my performance from 30 fps in Low settings to 45 on Ultra (i7 2600k CPU, GTX 570 GPU). These registry changes are reversible and there are no deletion of anything in the registry. It is all outlined in the forum link below. Please read the whole forum page to understand what is changing and if it applies to your setup, and edit the registry with caution. It worked wonders for me. Hopefully it can help some of you people out as well! People are reporting 50 to 80 percent performance increase and higher FPS.