how to cgminer scrypt when playing games

[xyzwarrior]

my cgminer line is  cgminer --scrypt -o stratum+tcp://pool.litebonk.com:3333 -u dgrfg -p gfergrt --thread-concurrency 10240 -I 13 -w 256 -g 2
if I set intensity to dynamic and play games, it will go to 12 and the hashrate will be only around 20 khash. If I set it 13 it's laggy in game. My card is 7970 @ 1038/1600