2x GTX 670 - no video on boot

[GLaDOSDan]

Hey guys,

I've been running a single GTX 670 for around 6 months now with no issues. The other day I added a second 670 and I am running them both in SLI.

My motherboard is the Rampage IV Extreme and I've got one card in the top most PCI-e slot and the second card in the fourth slot. SLI is working great and once I'm in Windows 7, all is good.

My problem, however, is that when I shut down my rig overnight then go to boot up ~12 hours later, I get no input to either of my displays (a Dell U2711 hooked up via DVI-D and an Asus VE278Q via DisplayPort, both connected to the top 670).

Windows seems to boot okay, I just don't get any video. The only way to resolve this seems to be pulling out both the DP and DVI-D connectors out of the top 670, then putting them into the bottom 670, then rebooting..

But even that doesn't solve the problem. After I've done that, I have to take the cables out of the bottom 670 and put them back into the top 670. After another reboot, Windows will boot correctly.

This behavior isn't experienced when I shut down for 5-10 minutes then reboot, it only seems to be when the system is left overnight.

I've updated my motherboards BIOS to the latest revision and that also hasn't resolved the issue.

Any help would be much appreciated, as I have no idea what's going on here.


tl;dr - SLI 670s, no video on boot however Windows starts fine. Have to reboot several times and disconnect/reconnect video cables in order for video to appear on displays.

 

[UkGouki]

what power supply are you using?

it could be related might even be cold boot causing it, my old psu which was a antec 500w hated my 8800 sli setup it also hated normal cold boots eventually i just had to leave the system on overnight, until i got my new psu which fixed a simular issue..

 

[GLaDOSDan]

what power supply are you using?

it could be related might even be cold boot causing it, my old psu which was a antec 500w hated my 8800 sli setup it also hated normal cold boots eventually i just had to leave the system on overnight, until i got my new psu which fixed a simular issue..

Thanks for the prompt response. I'm using an AX750 at the moment. Do you think that may be the issue? I don't see any instability when running both Prime95 and Furmark, the PSU seems to handle extreme load just fine.

 

[UkGouki]

should be perfect tbh the ax 750 more than capable of sli 670's.

what i would do is double check all connections it might even be somthing as simple as a loose cable.

 

[GLaDOSDan]

Yeah I've already reseated both GPUs and completely pulled out and reconnected all 4x 6-pin PCI-e power connectors at both the PSU and GPU side of things. At no point do the two green LEDs on my ASUS GTX 670s go out either (the ones that indicate power coming through the 6 pin PCI-e power connectors).

 

[UkGouki]

Yeah I've already reseated both GPUs and completely pulled out and reconnected all 4x 6-pin PCI-e power connectors at both the PSU and GPU side of things. At no point do the two green LEDs on my ASUS GTX 670s go out either (the ones that indicate power coming through the 6 pin PCI-e power connectors).

hmmn have you looked at the pins on the monitor connectors tried using Vga or hdmi?

also check bios see if legacy pci:e is enabled for video output without being infront of the pc to look myself and see it hard to diagnose now.

 

[GLaDOSDan]

The male ends of both cables look fine, as do the female ports on the cards. I don't think it's an issue here as these cables have worked fine for the last 6 months or so, and both connections are working when I shut down at night. The cables aren't moved or touched at all inbetween shutting down at night where everything works and booting up in the morning where the issues appear.

Just booted into the BIOS and went through every menu looking for a mention of Legacy PCI-e, couldn't see anything.

 

[UkGouki]

what motherboard do you have it should be under display options can be named different pci:3 or onboard etc

 

[GLaDOSDan]

what motherboard do you have it should be under display options can be named different pci:3 or onboard etc

I'm running a Rampage IV Extreme, can't see any reference in the manual or in the BIOS to any of the options you've mentioned.

 

[UkGouki]

found it >>

need to select all to pci gen 3

hopefully this fixes it for you

 

[GLaDOSDan]

Ah, yeah I saw that when I was in the BIOS. They're all already on GEN3.

 

[UkGouki]

then i havent a clue apart from a possible psu or cable issue if thats set to pci gen 3 it should be working perfect :-/

 

[GLaDOSDan]

then i havent a clue apart from a possible psu or cable issue if thats set to pci gen 3 it should be working perfect :-/

Oh well, thanks for your help thus far!

My issue appears similar to the one reported here: https://www.overclockers.com/forums/showthread.php?t=692920

Before I boot up tomorrow I'm going to remove the bottom card and remove the SLI bridge to rule out an issue with the top card. Until then, any further ideas would be much appreciated. Thanks!

 

[Mysterae]

I'm not familar with your motherboard, but my Gigabyte has a bios setting that goes along the lines of "Init Display First" as in initiate what display to use upon booting. If you have this in your bios make sure it is set to PCIE.

It could also be a quick boot setting or your system boots up quicker than your monitor takes to wake up!

 

[GLaDOSDan]

I'll take a look at those settings and report back - thanks.

Edit: I've now disabled "Fast boot" - will see what happens tomorrow

 

[GLaDOSDan]

Alright, so disabling "Fast boot" didn't change anything when I booted up this morning unfortunately.

Here's what happened this morning:

1) Boot up with fast boot disabled, both cards in SLI - no video
2) Shut down, disconnect SLI bridge
3) Boot back up, video is displayed
4) Shut down, reconnect SLI bridge
5) Reboot, video is displayed, all is normal

Does this mean there may be some weird issue with my SLI bridge then? This has just confused me even further

 

[Mysterae]

That's a shame disabling fast boot didn't work. Have you tried it with either gpu in the primary slot? Good luck mate.

 

[GLaDOSDan]

Yeah I've tried swapping them around and that didn't do anything either.

 

[Bang]

All enabling fast boot does is tell bios not to bother with every single check it can make. Enable it unless you enjoy wasting precious moments of your life watching your computer boot.

It sounds to me like its a problem with your sli bridge. Since you've checked the first one wihtout the second installed, do the same check with the second to make sure its not a defect in the second card.

Also, I noticed you have them installed in slots one and four. Try slots one and three (as per the instructions for just about every motherboard manual I can think of.)

Make sure you are only using one (the card in slot one) for video output. If you want to run a third monitor it will have to be from a third card, not sli-bridged, typically a card thats used for PhysX.

And yes, as above, make sure the init display first is set to pci-e. The only other thinig I can think of is when you get no video hook your monitor(s) up to the onboard and see if display has defaulted to that (assuming you have an intel processor.) If it has, you might have to flash a new BIOS to get it to see both cards. I hope that helps.

 

[GLaDOSDan]

Thanks for the lengthy reply.

When I was putting the cards into the system I did some Googling to find out which PCI slots were best to seat the cards in, the only thing that came up clearly telling me what to do with my specific motherboard was this thread on Tom's Hardware: http://www.tomshardware.co.uk/forum/322524-12-asus-rampage-extreme-management-gpus


The table near the bottom of the first post is what I referred to. Is that information incorrect?


Both of my outputs are connected to the card in slot one, yeah. I don't have anything connected in the bottom card. I've also tried removing the new (top) card to test if my bottom card is working okay, and it is.

There's no onboard video out on this board unfortunately, but I've flashed the BIOS to the latest revision to try and rule out any problems there and that hasn't helped unfortunately.


Regarding the broken SLI bridge, I'll see if I can dig out another one from somewhere and report back with any findings I make.

Thanks again for your lengthy reply, much appreciated.


Edit: Well, that's interesting. The spare SLI bridge I had wasn't long enough so I decided just to boot with my normal configuration. As expected, no video on boot. I shut down the system before (I presume) Windows had had a chance to start loading. I then disconnected the SLI bridge and, yet again, no video. I left it slightly longer this time (not long enough for Windows to get to the desktop, but enough time for Windows to begin loading up) - then I powered down and reconnected the SLI bridge. A further reboot resulted in normal behavior and video being displayed.


So it seems that until Windows begins loading after leaving my machine on overnight, my SLI config won't work properly. Only after rebooting once Windows has begun booting do I get any video.

Weird...