SLI option grayed out with two EVGA Nvidia GTX 970s, cannot enable SLI

[Carthas]

Hello, and thanks for taking the time to read my post.

I have NEVER posted in this or any forum for help before. I’m always able to find solutions on here or somewhere online to any problem. But for this particular problem it seems the thread just dies and is never answered, or the solution is different for everyone.

I’m trying to do an SLI setup with two EVGA Nvidia GTX 970s. When I go to the Nvidia control panel, the option to turn SLI on is grayed out, and “SLI disabled” is selected by default and the only thing selectable.

According to the chart on EVGA’s website, my cards are compatible for SLI. The reason I didn’t buy two of the exact card is because the first card I had was 04G-P4-3975-KR, which has three display ports, one HDMI, and one DVI. I have three Asus 144hz monitors that have to use the dual link DVI cable that comes with them in order to use the 144hz refresh rate. I have tried using dual link display port adapters and the screen flickers, and the monitor keeps popping up an error message.

So next I purchased 04G-P4-2977-KR, which has two DVI ports, one display and one HDMI. This way I’m able to plug all 3 monitors into DVI ports for the 144hz refresh rate, 3d vision, and NVidia surround. (Assuming I can get SLI to work).

My hardware:
• I have this motherboard.

• 16GB DDR3 RAM (1600mhz default speed, never touched any speed settings.)

• Intel i7 2600k cpu (safely overclocked, idles at 31C with aftermarket cooler).

• 750 watt corsair PSU

• Windows 7 64 bit

• 04G-P4-3975-KR and 04G-P4-2977-KR GTX 970 cards.


I have tried the following:
• Uninstalling the drivers using a program called “display driver uninstaller”, which gets rid of everything video driver related from safe mode. After which I did a clean install.
• Swapping the cards around in their PCI-E slots.
• I tried two different SLI bridges, even flipping them around and also plugging into both connectors on the cards separately.
o I even plugged in both connectors at the same time hoping one would work.
• Checked all power connectors and made sure everything is seated tightly.
• Disabled onboard video in bios, along with some stuff I’m not using.
• Updating the BIOS here using the Windows executable file option.

I’m currently at work right now and cannot provide screenshots or anything until later tonight. But I would greatly appreciate any help or suggestions! I don’t know what to do!

Thanks

 

[Skeefers]

Do you have your displays all plugged into the same card, or does each card have a display on it? SLI will only work if all of the displays are connected to the same card.

Look at the Connection Details section on this page for more info: http://www.nvidia.in/object/sli-technology-multimonitor-in.html

 

[Carthas]

Do you have your displays all plugged into the same card, or does each card have a display on it? SLI will only work if all of the displays are connected to the same card.

Look at the Connection Details section on this page for more info: http://www.nvidia.in/object/sli-technology-multimonitor-in.html

I have two displays plugged into the card that has two DVI ports, and one display plugged into the DVI port on the other card. So that would stop it from enabling in the software?

And if I have to have all displays plugged into the same card, I'll just have to give up the 144hz like I was hoping for and use an adapter for the third monitor. (Since I have to use a dual link DVI cable without an adapter to get the 144hz).

I'm going to plug all 3 displays into the same card tonight, and I'm sure it will work right away. I can't believe THAT was the problem; the most basic thing. I should have read more about it before setting up SLI. I just assumed I could plug displays into both cards at the same time. But I'm still glad I asked, because I was ready to RMA one of them and get an identical card. I'm also surprised that in all of my research I never came across anything explaining about having everything plugged into only one of the cards.

Thanks for your answer and I'll reply tonight if it works.

 

[Skeefers]

Yes, using multiple cards for your displays like you are disables SLI.

As far as I can tell, you should be able to do what you want by using a combination of the DisplayPorts and the DVI ports on either card. Do your monitors have DisplayPort connectors on them, or only DVI? You should be able to use either of the following cables/adapters depending on whether they have the DisplayPort option on them.

Straight-through DisplayPort

DisplayPort to DVI Adapter

Both of your cards have 3 possible connectors to use for the 144Hz refresh (discounting HDMI), so this should work fine for you.

 

[Carthas]

There are no displayport connectors on the monitors. I do have adapters I recently bought which claim to be active displayport to DVI adapters. When I just had one video card and all three monitors plugged in (2 display port/DVI adapters, and 1 DVI), the monitors that had the adapters would flicker and give an error message saying to use the dual link DVI cable that came with the monitor.

http://www.amazon.com/gp/product/B00DYRQXMK?psc=1&redirect=true&ref_=oh_aui_detailpage_o06_s01

So I was hoping to be able to plug all three monitors in with their native dual link DVI cables. But maybe it will work if I only have one of them plugged in with an adapter, and the other two monitors straight into the two DVI ports on the same card.

 

[Skeefers]

Ok, gotcha...I didn't fully understand what you were saying about the flickering before I guess. Hopefully that will work for you; if not, let me know and we can try some other stuff.

 

[Carthas]

Ok, gotcha...I didn't fully understand what you were saying about the flickering before I guess. Hopefully that will work for you; if not, let me know and we can try some other stuff.

This is what I still get with only one monitor plugged in:

http://i58.tinypic.com/rgvukz.png

 

[Carthas]

I reinstalled the drivers again, and it's still exactly like the picture above. I don't know what to do now.

 

[Skeefers]

I don't know what to tell you; I'm out of ideas. The only thing I can think of is that because they aren't identical cards, it won't allow you to do SLI with them, but I've seen it done with cards much more different than the ones you have, so it baffles me that two cards as similar as yours wouldn't work. Sorry man; wish I could help, but I'm stumped.

 

[gotovato]

Do you have any other devices plugged into any other pcie slots? Network card? Sound card? Anything? You should open up gpu-z and make sure both cards are running a x8 speed. Sli won't work with anything lower then x8 on both cards.

 

[Carthas]

Nothing else plugged into any PCI slot. I'm using a usb wifi network device, and on board audio. Here is the side by side gpu-z info for the cards:

 

[gotovato]

This might sound stupid, but you did put the sli bridge on right? If so, maybe it's defective? That's about the only other thing I can think of.

 

[Carthas]

This might sound stupid, but you did put the sli bridge on right? If so, maybe it's defective? That's about the only other thing I can think of.

I have tried two different SLI bridges. Together and separate, in both positions.

 

[Carthas]

I'm going to start from square one again and swap the cards around, etc, etc.

 

[gotovato]

Ok. Sounds like you've tried everything. I've only seen this issue once before, with 970's and an asrock board before. Last resort, try calling asrock support see if they can help