Originally Posted by Verbatim47
The GTX 260 has an automatic 2.0 PCI-E slot. I think you are talking about SLi? If you are then SLi is meant for games that have been coded for multi-gpu graphics. Most games can't take advantage of the performance anyway, I speak from experience with my dual SLi 7800gt's. One performed as good as 2 did.
For your specific question, the 8x * 8x versus the 16x, I personally can see no performance decrease or increase.
That was the 7XXX series!
The 7 series was the first series to have SLI abilities and they sucked! Now with the 8xxx, 9xxx, and 2xx series, SLI has huge performance jumps!
The drivers for the 7 series were shoddy at best as well.