Wolfshadw :
Not likely. A GTX 1080Ti will barely exceed PCI-E 2.0 standard throughput. A GTX 1060 will not.
-Wolf sends
Though throughput differs based on bus size, regardless...
For example, running a GPU at x8 instead of x16 (same difference as 2 vs 3), even if the GPU is not bounded by throughput, will introduce some inefficiency... I imagine it is because the transfer rate is more limited. Obviously not something to replace a motherboard on, but it probably introduces some marginal drop in performance. Overall, it's not an issue worth solving. Thank you Wolfshadw