GTX680 3-way SLI w/ 2-way bridges

[Funkengreuven]

I have an ASUS Rampage Formula 2011 with two MSI GTX680 FROZR cards. I just bought a third 680 and tried to install the 3-way bridge that came with my MB. It will not fit because the fan shrouds prevent the 3-way bridge from fitting down on the card slots. I've seen other folks use three 2-way bridges (which is what I want to do), but I've seen two different layouts for the connections and don't know which one is correct. Also, I can't find a spot on any site that shows how it's done on 600 series cards, only older models. Anyway, here's what I've seen:

http://www.anandtech.com/show/2403

http://www.xtremesystems.org/forums/...ay-SLI-results

I appreciate any help you can give! Don't know if it will, but I don't want to mess up one of my cards by wiring them wrong...

[Random Murderer]

Both layouts are correct. As long as there are bridges connecting cards 1 and 2, cards 2 and 3, and a long one connecting cards 1 and 3, it will work. Orientation of the bridges does not matter.

[20mmrain]

Originally Posted by Funkengreuven

I have an ASUS Rampage Formula 2011 with two MSI GTX680 FROZR cards. I just bought a third 680 and tried to install the 3-way bridge that came with my MB. It will not fit because the fan shrouds prevent the 3-way bridge from fitting down on the card slots. I've seen other folks use three 2-way bridges (which is what I want to do), but I've seen two different layouts for the connections and don't know which one is correct. Also, I can't find a spot on any site that shows how it's done on 600 series cards, only older models. Anyway, here's what I've seen:

http://www.anandtech.com/show/2403

http://www.xtremesystems.org/forums/...ay-SLI-results

I appreciate any help you can give! Don't know if it will, but I don't want to mess up one of my cards by wiring them wrong...

I have seen pics of people using 3 way sli with 2 way bridges. However when I tried using 3 way sli with my GTX 680's my system failed to see the 3 cards (It only saw 2 cards). I tried 6 different bridges with the same result and so I know it wasn't because the SLI bridges were broke. I am sure there could have been another reason like for example like Drivers.

But I mention it because it maybe safer to go with a 3 way sli bridge instead of 3 two way sli bridges. It's just my experience.

[Random Murderer]

Originally Posted by 20mmrain

I have seen pics of people using 3 way sli with 2 way bridges. However when I tried using 3 way sli with my GTX 680's my system failed to see the 3 cards (It only saw 2 cards). I tried 6 different bridges with the same result and so I know it wasn't because the SLI bridges were broke. I am sure there could have been another reason like for example like Drivers.

But I mention it because it maybe safer to go with a 3 way sli bridge instead of 3 two way sli bridges. It's just my experience.

Funk, if that's the case then you have a few options. Cut or remove that black piece of metal that's causing the problem, run 2-way SLI and return the third card, or change the coolers(watercooling would be your best option there).
Other than those options, seems like you're screwed if 20mmRain is right and 2-way bridges won't run 3-way SLI on 680s.

[20mmrain]

Originally Posted by Random Murderer

Funk, if that's the case then you have a few options. Cut or remove that black piece of metal that's causing the problem, run 2-way SLI and return the third card, or change the coolers(watercooling would be your best option there).
Other than those options, seems like you're screwed if 20mmRain is right and 2-way bridges won't run 3-way SLI on 680s.

Ohh Funk.... I read your post a little closer now and I now see your problem. Like Random Murderer said....If what I said is right for all SLI cards.... then yeah whats listed above are your only options.
However if this is true what a horrible design flaw!

But it seems something like this setup may work if you don't mind the looks....If this is something you would like me to test let me know and I can do it for you since I am using 3 way SLI right now.

[Random Murderer]

Originally Posted by 20mmrain

Ohh Funk.... I read your post a little closer now and I now see your problem. Like Random Murderer said....If what I said is right for all SLI cards.... then yeah whats listed above are your only options.
However if this is true what a horrible design flaw!

But it seems something like this setup may work if you don't mind the looks....If this is something you would like me to test let me know and I can do it for you since I am using 3 way SLI right now.

http://www.techpowerup.com/forums/at...1&d=1345225251

If you wouldn't mind, I'm actually curious as well.
I know that setup works for 5-Series cards. Whether it works for 6-Series cards is yet to be seen.

[Funkengreuven]

Thanks for all the feedback. 20MMRain, if you wanna give it a go, I'd appreciate it. I have various brand/lengths of 2-way cables I've either bought or collected through upgrades. I'm going to try them when I get home from work today. If you test too, then maybe we can rule out an additional variable if one works & the other doesn't. Otherwise, I'll reply with the results later today.

Also, I took the fan shround off one of the card last night (absolute nightmare), but it still wouldn't fit. It came very close, but when I pushed the bridge onto the connector it pushed the other side up at an angle. The part that's blocking the bridge with the fan shroud off is the main aluminum arm that mounts to the faceplate and supports the weight of the card. I can't really cut that without making the card unstable. In other words, if the above doesn't work, then I'm out of luck. Someone ought to make a 3-way bridge with longer feet!!!

Thanks again...

[Random Murderer]

Originally Posted by Funkengreuven

Someone ought to make a 3-way bridge with longer feet!

Now there's a mod idea! PM sent.

[20mmrain]

Originally Posted by Random Murderer

If you wouldn't mind, I'm actually curious as well.
I know that setup works for 5-Series cards. Whether it works for 6-Series cards is yet to be seen.

Thanks for all the feedback. 20MMRain, if you wanna give it a go, I'd appreciate it. I have various brand/lengths of 2-way cables I've either bought or collected through upgrades. I'm going to try them when I get home from work today. If you test too, then maybe we can rule out an additional variable if one works & the other doesn't. Otherwise, I'll reply with the results later today.

Also, I took the fan shround off one of the card last night (absolute nightmare), but it still wouldn't fit. It came very close, but when I pushed the bridge onto the connector it pushed the other side up at an angle. The part that's blocking the bridge with the fan shroud off is the main aluminum arm that mounts to the faceplate and supports the weight of the card. I can't really cut that without making the card unstable. In other words, if the above doesn't work, then I'm out of luck. Someone ought to make a 3-way bridge with longer feet!!!

Thanks again...

Sorry guys it took me so long to get back to you..... But the answer is....

YES it does work in the configuration I listed above.... I am on my computer writing this to you now while my cards are plugged in with that configuration. As soon as I took the 3rd SLI bridge off again it started missing the 3rd card. So I think you have to have either this setup or a 3 way sli bridge for it to work. Otherwise it won't work with just two.

[Funkengreuven]

Thanks for the help! I managed to get it working by following the diagram on the post.