When in SLI using two x16 PCIe v. x16 and x8 PCIe

[Trivius]

I recall reading something about when in SLI there is no gain in using two x16 PCIe over a x16 and x8 PCIe. I am going to be using a EVGA 1366/X58 Classified 3 and am wanting to confirm the best performance gain for SLI. To note one point of concern though, currently when using a single card (EVGA 680GTX Classified) in the first x16 PCIe Windows 7 freezes while loading, I had prior sent the GPU in for repair, but it was cleared with no issues found--I am presuming that SLI may remedy this issue that is only a guess on my part though.

Also, was there something about when using more than one GPU you only need to use one 8-pin connecter on the subsequent cards?

 

[sparkey247]

i don't know if sli will remedy the issue you having, When the video card was cleared if you are still having he same issue have you tried to put card into another slot or better yet another pc. the freezing while loading could be another issue as well. i don't know about using on 1 8pin on secondary cards. there is a difference between 16x and 8x, but it is so minute that you will never notice you can google for more info but i think on AVG its like 1 to 3 FPS difference, I wondered 8x vs 16x Myself as im planing on adding a second gtx980 to my 4790K which only has 16 lanes to start

 

[Trivius]

Yes, it works in all slots, with exception to the very first one, which technically it does work in that slot as well, though when windows begins to load the wavy Windows logo stops moving after about 2-seconds and then the computer just hangs until I reboot it.

 

[sparkey247]

will i boot into windows from slot 2? as being the only card!

 

[EarthDog]

It's about a 1% difference at 1080p between 16x and 8x or in this case 16x/8x. You can say a specific FPS as that would vary, but a % value is limitless.

 

[sparkey247]

also do you have a different card to try in slot 1. reason im asking is we want to rule out there being anything wrong with slot one

 

[funsoul]

You'd only experience a noticeable difference between x16/x16 and x16/x8 if doing benchmarking ala hwbot. For gaming, as has been pointed out it'd only be 1-2-ish fps difference.