GTX 1060 with H310

Solution
No, 310 does have some PCIe 2.0 lanes avialble, but it has 16 lanes of PCIe 3.0.

But in reality, it would not matter. PCIe 3.0 has twice the bandwidth of 2.0. So 8 lanes of PCIe 3.0 equal 16 lanes of PCIe 2.0. The 1060 will run fine on 16 lanes of 2.0. Even the 1080ti would only see a few percentage points difference running 8 lanes vs 16 lanes and it requires a lot more bandwidth than the 1060.
No, 310 does have some PCIe 2.0 lanes avialble, but it has 16 lanes of PCIe 3.0.

But in reality, it would not matter. PCIe 3.0 has twice the bandwidth of 2.0. So 8 lanes of PCIe 3.0 equal 16 lanes of PCIe 2.0. The 1060 will run fine on 16 lanes of 2.0. Even the 1080ti would only see a few percentage points difference running 8 lanes vs 16 lanes and it requires a lot more bandwidth than the 1060.
 
Solution