(In reply to comment #65)
> (In reply to comment #63)
> > Created attachment 90542 [details] [review] [review] [review]
> > possible fix
> > 
> > Thanks for tracking this down.  The attached patch should fix the issue. 
> > With this fixed, it may be worth checking to see if you can reliably use the
> > tweaked clocks on certain oem boards (basically disable the ni code added to
> > fix bug 69723).
> 
> I reverted patches from bug 68235 as suggested, applied the proposed patch
> to disable mclk spread spectrum and I'm now running this new kernel. First
> observation: without patches from bug 68235 prior to disabling mclk ss, I
> was unable to load a session without it hanging in less thant a minute. It's
> now rock solid running GPU clock at 830MHz and memory clock at 1300MHz. I'll
> run a couple of other tests, but I think we got it!

Sadly, I pushed the card a bit harder with Serious Sam 3 and it hanged again.
So I'll try two different things:
- keep spread spectrum disabled only for mclk but reapplying both patches from
bug 68235;
- disable all spread spectrum without reapplying the other two patches.