Otis11 ...

I may be old but if you beat me hard enough with a stick long enough I can learn new tricks

You got me thinking about the interaction between the GPU components and I realized I was blinding myself with the *shaders shaders shaders* mantra.
While not for the same reasons you state in your ratio theory (harmonic distortion, frequency collisions ... dude... what??? not saying you are wrong, I'm just not smart enough for that), I decided to see if I had my shaders so high it was preventing my memory OC which in turn was starving the very shaders I think are the catz azz.

Damn , damn, damn ... I gotta listen better to you whippersnappers ... I turned my shaders down one notch (1620) and my memory up (1215). While I did get a couple of errors this morning I have since been returning a little FASTER than before (~10 min per WU). So yes, utlimately I think ratios are important and will continue working on finding the sweet spot for my cards.