How does epoll work internally?

How does crossfire work internally?

• (Bad way of describing my question i know)Ok so I was thinking about running 2 cards and crosfiring them. I know it will usually help in performance but not alway... Right? But my real question is how does it help in performance if when u do cross them it cuts the pcie down from 16x to 8x. In my logic that's kind of defeating the purpose. Now I know I'm wrong cuz I've seen benchmarks of before crossfire and after but could someone explain how it would increase in performance if you are cutting the pcie slots in half?

• Answer:

  If you have PCIe 16x and PCIe 8x slots, it will run at the 8x speeds.