Hi guys, been reading through this thread, sorry it has taken a while for me to jump in. I've gone through and read through all of the posts, and thought I'd test to see if my build/660 Ti was having any of the issues you are describing.
First, I've never seen any of the errors described in FCPX. I've done a couple of smaller projects in it at this point, and have done renders, effects, exports to Compressor, and conversions through Compressor stand alone. To go a little further, I installed the demo of the NeatVideo Noise Reduction plugin that was mentioned to absolutely cause crashes when you try to turn on the GPU. For me, it saw the GPU, I ran it through benchmarks and analytics. Got this as my result:
Also, the effect rendered correctly, and I could export a clip using Compressor with the effect applied.
Secondly, I downloaded Pixelmator and attempted to cause issues as discussed earlier in this thread. I could go to full screen with no pauses, apply effects, and generally never saw any errors. Also, I checked my system.log after doing both this and FCPX tasks, and there were no
nvda channel exception errors anywhere in the log.
I'm including my Luxmark scores for both GPU and CPU+GPU
I don't know if any of this information is useful, but I'm more than happy to test stuff out or try to answer any questions I can. I don't guarantee I have answers, but I'll see what I can do!