So my STRIX 980 OC is running really hot, even with Bioshock infinite, which easily gets 250-300fps on ultra, I cap it at 60fps and my gpu is still reaching 70c to 80c my cpu only hits 60c at most. I am using the stock heat sync, one intake fan, and two outtake fans so that hot air escapes the case faster. I'm a bit of a noob at anything PC, are these safe temps? If they're not, What can I do without buying a radiator?
Load temps should be around 70c or so with an ambient of around 20c. Your temps are fine and well below any dangerous level. Increase airflow as much as you can - tidy cable management, adequate case fan speeds - even replace them with better ones. If you're keen to get the temps down just create a custom fan profile in msi afterburner - takes <1min to do so.
GPU boost works by having either a pwer target or a temp target. Your card is designed to run as fast as it can up to a set temp.