The fix dates back to 2009, but it may be the answer for many who can't figure out why their gameplay is so sluggish.
http://www.reddit.com/r/battlefield_4/comments/1puiok/getting_cpu_lag_in_battlefield_4_i_found_a_fix/
http://www.reddit.com/r/battlefield_4/comments/1puiok/getting_cpu_lag_in_battlefield_4_i_found_a_fix/