Originally Posted by Yaboze
That's weird, I thought when I put my 9600GT in as a PhysX card, it ran at PCI-E 1x for the 9600GT and my main card at the time, a 260, still ran at 16x.
It's motherboard dependant.
My Gigabyte board automatically splits the PCI-e lanes whenever a 2nd card is present. It was never really designed for serious 2 card graphics solutions... it doesn't support sli, but technically crossfire, but it splits the lanes... so there are obvious disadvantages to it.
It really all depends on your motherboard's implementation