What slots should I put the second one in

[brandon9455]

I now have 2 RX480s which I plan to run in crossfire, the cards are really close if I put it into the 2nd pcie slot could I put it in the bottom slot and not lose any performance? Motherboard : Gigabyte X370 gaming k5

 

[Petrossa]

You have to put it in the 2nd slot for Crossfire purposes.
The 3rd slot is only wired for x4, and suitable for add-in cards only.
As long as you have decent airflow through your chassis those cards will be fine.