Dual Asus Direct CUII 290X OC Cards at x8, x8 lanes?

clutchc

Titan
Ambassador
It used to be that single GPU cards would not suffer when running in CF at x8, x8 lanes. But cards have improved lately. Is that still the case? I'm wondering what folks feelings are about any PCIe bandwidth bottleneck when running two of these: http://www.asus.com/Graphics_Cards/R9290XDC2OC4GD5/overview/
...in CF on an x8, x8 board.

Btw, it wouldn't be in the board in my sig below. That board is indeed x16, x16 lanes. This is the board they would be in with an i5-4690K: http://www.msi.com/product/mb/Z87-G55.html#hero-overview