I need help understanding PCI-E x16, x8, x4 and x1

[paintboy131]

I have an Asrock FATAL1TY 990FX Killer and it has 2 PCI-E x16's, 2 x1's and one x4 (in an x16). So, I understand that GPU's go in x16 slots right? And the second one for SLI goes in the x4 slot? Then why are there 2 x16 slots? And can I put x1's in x16?

 

[kanewolf]

According to the manual page 19 (you have read it right?) ... slots PCI-E 2 and PCI-E-3 can be used with two graphics cards in SLI or crossfire. They will both get x16 system access width.

You could put a x1 card (network, sound, other low bandwidth card) in a x16 slot. It will work. The x4 slot would typically be used for a RAID controller or a 10GE card.