Renderdevice.renderaheadlimit

Hello guys. my settings that.

i7 4930K 4.3GHZ. (OVERCLOCK)

980Tİ EXTREME EDİTİON AMP

16GB RAM

So. İ playing 1080p 144hz Ultra.. My fps 130-100 always  changing. İts oke. But this command whats that "Renderdevice.renderaheadlimit." Orginal -1 Yea i know when i write that so much fps drops. Same maps 70 80 i see. But when i write 2 its oke. But i feel grapichs color so bad. İ feel that. Is this possible???