Upgrade to 10Gb, worth it with my config?

[Etorix]

Technically the 3.0 x4 should handle 2.0 x8 bandwidth but I'm not sure how that works electrically.

No. A PCIe 2.0 x8 card plugged into a PCIe 3.0 x4 slot runs at PCIe 2.0 x4.

 

[Davvo]

No. A PCIe 2.0 x8 card plugged into a PCIe 3.0 x4 slot runs at PCIe 2.0 x4.

Rule is to take the lowest spec amongst the two. A x8 will not work at x8 in a x4, a PCIe 3.0 won't work at 3.0 speeds in a 2.0.

 

[winstontj]

Sorry if I was confusing, what I meant was that 3.0 x4 bandwidth should be equal to 2.0 x8 bandwidth "overall", not lane-for-lane. (8x1=8 and 4x2=8). The bigger point I was trying to make is that some cards & chipsets will negotiate down and run at 2.0 x4 in a 3.0 x4 slot, and others just won't work. So have to do homework/research before just buying 2.0 x8 cards and plugging them into 3.0 x4 slots.