Steam: Lockup, forced to restart computer

[duh]

Yea, my GPU temp drops when i tab out, but you can still see for a brief moment what the temp was before the minimize.

[Hypatian]

Hrm. I'll keep trying, but this looks like it's not going to work well to spot the problem, if overheating is in fact the problem. I played a new game three times. The first time, up through killing the dragon in training. The second time, up through killing the necromancer. Neither time did the temperature get very high (a bit lower than max playing Team Fortress 2, in fact.) The third time was going to be through the treasure hunt, but the system crashed at the very start of the necromancer fight. I have no idea what the temperature was then, but it was just fine after I rebooted, so... *shrug*

Since the problem appears suddenly and without warning, and prevents any useful recovery of information after the machine needs to be power cycled, I'm not sure what to do.

[duh]

I ran the game in windowed mode so i was able to view the hardware monitor after it had crashed. Overheating is very unlikely to be the problem, as you said it runs at a slightly lower temperature than source engine games.