But the double precision perf of M60 is very low and less than the K80 due to limitations of the Maxwell microarchitecture. So we could say K80 is the last decent dual-GPU Nvidia card...
Ah, sorry, I forgot about that one. The Tesla Maxwells came much, much later after the Geforce cards, so it wasn't very long until Pascal was released. To meet all the needs of the customer, Maxwell was likely not a good choice, but the single precision was much better than Kepler.
But the double precision perf of M60 is very low and less than the K80 due to limitations of the Maxwell microarchitecture. So we could say K80 is the last decent dual-GPU Nvidia card...