2x gtx 1080 SLI Fan Issue on GPU (2) only one fan working on the GPU

oke! I shall look into that. On a short note ive tried some other things with interesting results.

So the lay out of the mother board (MSI x99 Gaming pro carbon) is a bit odd. Because only PCI_E1 and PCI_3 have 16x lanes support. But in this configuration there is no spacing between the cards making the upper card run extremely hot (like 85degrees on valley benchmark). Not a good thing (imho). So i kinda anticipated this would happen and there for i opted for the configuration of having one GPU in PCI_E1 and one GPU in PCI_E5 this way two slots sit between the cards and cooling is sufficient. But, the PCI_5 slot only has 8x lanes. I checked the manual and what i understood from the manual is that then both cards would run in 8x lanes mode. I figured this was oke and went for this option. So just i swapped the cards a bit to see whether the Fan issue on the card in the PCI_5 slot would persist if i put the GPU's in the PCI_E1 slot and the PCI_E3 slot. And in this configuration actually both cards their Fans work perfectly fine. I used two Flexible sli bridges that i got with my Motherboard. Besides the million things this could indicate / mean two things came to my mind. 1: The HB Bridge somehow causes a problem or 2: The Issue is only there when a GPU is in the PCI_5 slot.

So i went to test whether there was a difference between the bridge being used with the PCI_E1 / PCI_E5 configuration. But the results where the same with either bridge (flexible/EVGA HB Bridge): The card on the PCI_E5 slot has only one fan working and one fan off.

So i start to think it must be a bios setup / motherboard glitch? Or it has something to do with plugging one GPU in a 16x lanes support and one GPU in a 8x lanes support. All though i wouldn't suspect that would give any issues since the manual clearly states that this motherboard is compatible with sli 2x and even sli 3x configs.

Also ive tried reinstalling NVIDIA's GTX1080's drivers. But no change happened. In the mean time i have also contacted MSI support. And before i installed my 2nd GPU i also have updated my bios firmware. Im going to check if i can reset my motherboard somehow and hopefully somethings happens. it is really narrowing down to this PCI_5 slot somehow not directing the card's back fan not to go on>? Could maybe tweaking the system Fan's rpm setting in the bios influence how the GPU fans get controlled?

i'll report back if anything has changed or when i have found new information. In the mean time im going to check this: "EVGA about semi passive mode fail"

Cheers

Do you mean to check with EVGA for a GPU bios update? Because im using MSI GTX1080's and MSI X99 motherboard. But the bridge is EVGA though. But i don;t think EVGA has a Bios update for my GPU / Motherboard right?

Ah ok! Ive updated them with my results from earlier. I havent had any reply jet, but i filed this issue first yesterday on sunday so i'll give them some time to look into it. I do have their latest bios update 1.3 for this motherboard installed, i also tried to downgrade to 1.2, but to no avail. Then i went back to 1.3 and cleared the cmos. Just trying things here. But still no luck. The thing must be a motherboard / bios glitch (or Mobo hardware failure? seems unlikely...). Because i can actually see when i turn on my pc that the fan that is not working and that it is actually never turned on at boot. So GPU 1 has two fans that actually go on when the pc turns on and then at idle they turn off when logging into windows. But GPU 2 (or whichever one that is in PCI_E5 slot) turns only the front fan on.

Such a crazy glitch driving me nuts. In the mean time im considering running both cards in the PCI_E1 and PCI_E3 slot. But then the upper card, GPU1, gets like 85 degrees. Now ive read that these pascal cards run a bit hot. But when gaming for like lets say 10 hours (just extreme example, but hey.. sometimes i actually do game for long looong times) then these temps of around 85, 84 can't be good right>? I mean the cards do it, but will it decrease their lifespan allot??

Thanks for the help, i keep this thread updated regarding this issue. i really do hope MSI will help me out on this one. And also whether this is Bug or a a hardware failure with just my unit motherboard. MSI has been pretty good with other issues i have had so pray they can help me with this one

Cheers
K

Ah ok good to know about those temps. Oke update: I got answer of MSI, not really satisfactory to be honest. Ive quoted their response below. I referred to the manual again to see wether PCI_E1 and PCI_E5 configuration are actually supported. I cant really decide actually. (pasted pic below from manual). All i know is that when i put both GTX1080's in the full 16x lane support mode, which is only PCI_E1 and PCI_E3 slot than i could tell the performance was getting a boost. So short conslusion. The X99 Gaming Pro Carbon is far from optimal (don;t do this ) in using two aircooled cards with a 40 lane processor, 8x lane support has a glitch on my unit and the 16x lanes config only is viable when both cards are watercooled. I'am contemplating watercooled, but i feel i have too little experience and don't feel like chucking out the extra cash at the moment. So i decided to send back both the GPU and Bridge. I just run my single GTX1080. Bit of a bummer since the rest of the build is totally up for sli config. But if i want to run 2x sli aircooled GTX1080's i just kinda need another motherboard. Since my CPU (i76850k) actually has 40 lanes it makes no sense having two GPU's in 8x lane mode, since ive read that GTX1080's actually like running both in 16x lanes. (kinda sucks, but hey). I allready checked for a potential motherboard that has one slot spacing between GPU"s in SLI 16xlanes config at the same time M.2 is installed, and supports 40 lanes with an ATX form factor. The only i could find so far is the gigabyte GA-X99-Designare. There are probably more out there. Only thing is, this thing costs a fortune, 420eu where i live, that in combination with another GTX1080 which is 750eu. If i would sell my current mobo maybe i get 250... 220 euro for it? i dunno. it would still costs me an additional 1k on my allready expensive build. So i think my best bet is to just update my GPU when the time is there.

Dat moment u realize u failed On the other hand.. i have a little bit the feeling that somehow the support for SLI GPU's in games isnt all that great... It kinda feels glitchy and sucky at times, except on the moment it all just works and the game supports it.

I tried GTA5, it actually was worse with two GPU's then a single GPU. (to be fair i didnt spend that much time tinkering with it trying to make GTA5 work in SLI)

MSI response:

Dear sir/madam
Thanks for contacting MSI technical support team.
Regarding your concern,please refer to the suggestions below to troubleshoot the issue.
1)Make sure that your graphics cards are properly seated and that the SLI bridge is installed correctly.
2)Sometimes, swapping the slots your cards sit in does the trick.
3)Verify that Windows Device Manager is showing two identical graphics cards in the Display Adapters section.
4)Ensure that SLI is enabled in your BIOS settings.
5)If you have an older motherboard, you may need to configure your jumpers to enable SLI. Consult you motherboard manufacturer's manual for instructions.
6)Make sure that you have an adequate Power Supply.
7)Get the latest drivers for you BIOS and video card.
8)One of your graphics cards may not be functional. Try installing them one at a time to make sure they both work.

Thanks for your cooperation in advance!
Best Regards,
MSI Technical Support Team


Pic from Manual:
http://imgur.com/a/86RSO