I was checking AsRock site and specifications of the motherboard x58 extreme6 for the pci-e 2.0 16x slot (i've checked the manual too), specifications say that the line works at 16x-16x for dual card configuration (sli/crossfire) or 16x-8x-8x for triple card configuration.
The question is, in the configuration with two cards, the third and final pci-e 2.0 16x slot will still work at 1x or will be turned off (0x)?

Thank's in advance for your help