Gaming suddenly laggy

Pninchan

Honorable
Jan 10, 2013
9
0
10,510
Hi, I was playing bioshock perfectly fine this morning on settings all maxed out. After about an hour it got really laggy like the fps was really low, I thought nothing of it and returned to it now and its still laggy. Any ideas what the problem might be?

My specs are
Processor: AMD fx 6300
Graphics card: RADEON HD 7870
RAM: 8GB