The game is capped to 60 FPS but since alpha is unoptimized its entirely possible that it needs to utilize more GPU resources to reach 60 FPS than other games (especially on Ultra).
Fans on top speed = near-100% GPU utilization usually, so I'd say lower your graphics settings and see if it makes any difference (disabling AA, SSAO and shadows seems to make the biggest difference).
Btw, does this occur in the main menu too, or only ingame?
