Issue when enabling SLI (GTX 970's)

[SilentEuphoria]

Morning Guys!

Last night i installed a second GTX 970 Strix into my computer, all connected fine and booted fine. The computer recognises both GPU's properly in all applications and even popped up to tell me "this system is capable of SLI"...

So i went into the Nvidia control panel to enable SLI, i clicked the option to enable and then upon pressing apply the changes started to load and then the screen went black (But still had a back light so was still receiving a video input of some sort) i assumed this was just the normal thing where it flicks black like when you update your graphics drivers or something, but it never came back on? After leaving it 5 minutes i forced a restart on the system and it booted up fine, but obviously without SLI enabled. I tried a second time just to be sure and it did the same.

System Specs are as follows:

Asus Z170 Sabertooth Mark 1
i5 6600K
2 x Asus GTX 970 Strix
4 x 4GB Crucial Ballistix DDR4
Evga 750G2 - 750w PSU
1 x 512gb Samsung SSD
1 x Seagate 2TB Drive

Operating System - Windows 10 64Bit
Bios - Flashed to very latest version
Graphics Drivers - Wiped using DDU after installing both cards and then updated to the newest drivers

I have tried both cards on their own and they function completely correctly... So i'm a bit stuck!

 

[ATMINSIDE]

BIOS up to date?

 

[SilentEuphoria]

Yeah! Got the latest UEFI off the Asus website last night...

I'm stumped!

 

[Johan45]

Did you install the bridge?

 

[JrClocker]

Do you have your monitor(s) plugged into correct ports on the cards? You can go to the NVIDIA website and it will tell you what port combinations are allowed in SLI.

 

[SilentEuphoria]

Did you install the bridge?

Yeah! Tried two different bridges, one of them was on my last SLI machine so i know it works!

Do you have your monitor(s) plugged into correct ports on the cards? You can go to the NVIDIA website and it will tell you what port combinations are allowed in SLI.

Only got the 1 monitor and it's plugged into the top card via HDMI..

Strangely though, when both cards are installed, if i try plugging it into the bottom cards HDMI instead of the top one, then there's no output. But if i take the top card out then it works fine in the bottom card...

 

[JrClocker]

Strangely though, when both cards are installed, if i try plugging it into the bottom cards HDMI instead of the top one, then there's no output. But if i take the top card out then it works fine in the bottom card...

NVIDIA has "rules" for what port(s) you can use for SLI...so it makes sense that you get nothing on the bottom card.

Found the link:

http://www.geforce.com/hardware/technology/surround/system-requirements

 

[SilentEuphoria]

Ahh that's alright then!

It's just such a strange issue... seems like it wants to work and then just goes blank

 

[ATMINSIDE]

Tried a driver one step older than current?

 

[SilentEuphoria]

Tried a driver one step older than current?

Just tried that! And the ones two steps older! All with proper wipes in between... No luck

Tempted to try a fresh windows install

 

[ATMINSIDE]

When's the last time you did a clean install? Was it before updating to 10?

 

[Lochekey]

Are you using the top 2 pcie x16 slots and not the lowest one?

 

[SilentEuphoria]

When's the last time you did a clean install? Was it before updating to 10?

Nah it had a clean install of Windows 10 when i built it a few months ago, but i still think its worth a shot.

Are you using the top 2 pcie x16 slots and not the lowest one?

Yeah the top two, can't get to the bottom PCIE 16X due to the case.