Tiny projects killing PPD on big GPUs

[Shirty]

I appreciate that it's very complex, I guess my point is that on GPUs where there is evidence of such huge variability in efficiency on WUs that are currently assigned, it might make sense to define these separately.

For example, my 1080Ti varies between 950K and 1.35M ppd. On the same pool of projects the 2070 Super varies from 1.1M to 1.5M. I feel like those are sensible ranges, whereas the 2080Ti can sometimes shine, effectively doubling the output of the 2070 Super (great, since it's double the price!), but on other WUs it's no quicker than the cards its capable of dominating.