The stutter will be occurring when the boost is activated and the massive voltage bump is applied. That's the reason, whether you want to accept it as the reason is up to you. The fact is if you had another 10% or more onto the TDP you wouldn't have had any down clocking.
But when you overclock, no boost is applied. "Boost" only applies at stock clocks, other wise it goes from 2D/Low power to max clocks.
Also when I locked full 3D clocks it happened, with force constant voltage as well, i had to test this because i initially thought it was dropping to 2D/Low power mode when stuttering, but this was not the case.
I don't know if this is AMD's fault, it might be. It might also be possible that AIB's and in this case Asus used their own bios, as do HIS, and the TDP set is for the non boost version of the cards. I've had a look around and can't see any mention of this happening on AMD reference boost cards but those are pretty rare now a days.
I'm just explaining what your issues were and how they could have been solved rather than just blaming it on crossfire or poor drivers when in this case that is not the issue and neither of those had anything to do with it.
It's AMD's fault because they let this happen on their cards.
"Boost" is a feature of the 7970 GHz cards, they created the feature, they created the problem. Yes AIB's may of exacerbated the issue, but nevertheless it's a great disappointment on AMDs side to not of thought the feature through.
You're explaining what other's issues were and assuming it's the same for my setup. Whilst at the same time assuming that a rather messy and clunky set of instructions that pretty much start "Do this at your own risk" and require 3rd party software (that doesn't work for every card), is an acceptable solution for the indignant consumer. When in reality it isn't.
I chose, given my situation, that i wasn't going to faff around with cards that cost so much. I should "just work". So sold them on and got the better solution for my money.
Something that could have been avoided, if AMD had thought ahead for crossfire (and supposedly their boost function).
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