The chip in my sig has been stable since launch, 3003B396. From all the threads I've seen it's about average as far as vcore required. I've had it to 5ghz on water able to pass some benches, 1.6ish vcore.

I agree with zalbard certainly the 920 is the better buy if you don't have a specific need for the extra cores, the overclocks are around the same.

In fact I would say the 920 is a much better chip for 24/7 since you can pump vcore and if it dies early you're not out the 1k that a 980 costs. I have been temped to stick my 920 in and crank vcore and run it at its max and use the 980 as a backup.