Can't run 4K resolution in SLI GTX 680 4GB

socal6801

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To anyone who can help. I recently bought a new Samsung U28D590D 4K monitor. I have twin GTX 680 4GB video cards running in SLI. The problem I'm having is when I run them in SLI I can only get 2560 X 1600 max resolution. Each card on it's own will run the 3840 x 2160 max resolution with both cards installed but, not in SLI. I've tried each individual card, swapping order, changing sli bridges, and reloading (fresh install) of the newest NVidia drivers. I also have the most recent Bios for each of my cards. The one catch is the cards are not made by the same manufacturers. I have one GTX 680 4gb from EVGA and one GTX 680 4gb from Gigabyte. I have not had any issues running the two cards together but, I'm wondering if this could be an issue running 4K resolutions. Oh yeah and my connection to the monitor is via a singe display port cable.

Seriously, anyone who can solve my issue will forever have my gratitude.

Thank you,
 

benfulks

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The cable supports PC resolutions of up to 2560x1600 and all HDTV resolutions including 1080p. It also supports uncompressed audio and extended color depths of up to 12-bits per component ensuring flexibility to meet most display application needs. DisplayPort to DisplayPort Version 1.1a Cable.

there is an article on why you may only get to 2560x1600. this is straight from the top of google sorry i dont have a source.
 

socal6801

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You are a life saver!!!! I connected the display with an HDMI @ 30hz and it booted right up at 4K resolution in SLI. Honestly, I had no faith it would work but, I had tried everything else. I already knew I wasn't as smart as I thought I was and this is just another confirmation.

Thank you very much!
I don't know if the displayport cable I have is V1.2 or not so, I'll start by getting another cable. I assume if that doesn't work than the issue is with the ports on my video cards. That will be a very expensive fix. Although, maybe a couple of new cards would be better suited for gaming at 4K anyway.

Thanks again!

Cheers!
 

benfulks

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well i would say look in to research to see if there is software updates to the cards that can push them to 1.2, if thats the case you can save your money on the gpu. right now we are at the in between stages of interface revision. we need display port 1.2 hdmi 2.0 and so on. hdmi 2.0 will get you 4k at 60hz, but to my knowlage there isn't a gpu out there that supports it (yet). im hopping a lot of this will be fixed with simple software updates, but there is a chance that we early adopters are going to get screwed on this.
 


When you were running without SLI at 3840x2160, weren't you using the same display port cable and display port output on the graphics card? Doesn't this prove that the display port connection and cable are suitable?
 

socal6801

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I am able to run either card at 3840 x 2160 as long as I don't enable SLI. As soon as I enable SLI it falls back to 2560 X 1600 and the option for 3840 X 2160 is gone. When I hooked up the HDMI cable I could run the cards in SLI and display UHD resolution. It's probably a long shot but, I figure I would try a DP cable I know is V1.2 compatible. I have another computer with GTX 480s in SLI. I'm pretty sure those are not DP 1.2 compatible but, I'm going to connect the monitor just for giggles and see what I get.
 

monevthegale

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I'm having the same problem with two 770 4GB cards. I'm using the DP cable that came with the monitor which is 1.2 and I can get full 4K with SLI disabled, but once I turn on SLI it goes down to 2560x1440 with no options to go higher. I've also tried several different drivers, none of which fix the problem. I'm currently going through Nvidia tech support trying to find an answer.
 

benfulks

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again the cable the card and screen can be optimized for this but the sli software may not be. so SLI is running 1.1 (software) while non SLI is running 1.2 (software). i would post this on the nvidia forums and see if you can get an actual employee to check it out. should be just an update on their part.
 

monevthegale

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I'm pretty sure Nvidia already has 4k SLI support since there's plenty of SLI 4K test reviews out there.
 

superxero044

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If anyone comes up with a solution PLEASE post it here. I am having same problem.

Samsung 28" U28D590D

I have 2x GTX 670. They work fine in SLI.

However if I enable SLI I can only select 2560 x 1600 and cannot pick the native resolution of 3840 x 2160.

If I disable SLI I can pick the Native resolution no problem.

I am on driver 337.50.
I am connecting with displayport cable.
Installed samsung monitor driver
 
Some of these 60hz 4k monitors are getting 60hz by connecting 2 HDMI cables to the monitor and with displayport or two HDMI cables, they actually use 2 monitor surround to achieve the 4k 60hz resolution. Check with the surround settings with the displayport connection, or attempt to use both HDMI connections.