The Zalman VF1000 keeps the M2090 ... uh ... working ok. As discussed there is no way to know the GPU temp like there is with the C2070.
I have compared the speed of the M2090 to the C2070 (overclocked I think) & the M2090 is faster. Almost twice as fast. But, the M2090 is in a faster system; the M2090 is in a i7-990X versus the C2070 in a i7-920. Both CPU are OC-ed to well over 4 GHz, but a utility I have that came with a commercial number-crunch software shows the PCIe bus in the i7-990X is almost 10X faster than the i7-920. Mother boards are identical.
When there is a lull in the current crunching I will upload a few screen shots. Still, the C2070 is substantially faster than the i7-990x crunching by itself which had been the comparison. And, I must def find the time to drop in the extra i7-990x.