Guild Wars 2

If it’s temperature, there’s not much Anet can do, but then, assuming it is just seems like a stab in the dark in the first place (if not a bad one; the game DOES run machines hot).

Install MSI afterburner and run it while the game is running; use it to check your temperatures from time to time. If that’s the problem, it’s a good program to tweak your GPU.

To address with more obvious sources of problems, you have updated your drivers to the latest version, right?

Instead of actually underclocking your cards, you can try just undervolting them a bit, provided you’re using a GPU that supports that. There’s always headroom there (afterall, if you can OC on stock voltage, you can always undervolt at stock clocks). That’ll also knock down temperatures, and even more effectively from what I’ve seen, but without costing performance.

If it’s something that’s happening after awhile, it could well by GPU temperatures as well. This game has been making a lot of peoples’ cards run extremely hot.