Win10: 3rd graphics card goes missing?

[Darkphibre]

I've put together a bit of a beast for doing Photogrammetry (3D scene reconstruction with photographs). As this software is CUDA and CPU heavy, I want to continue to use my old GTX660 with the new dual GTX1080s. But when all three are installed, the GTX660 rarely shows up (maybe 1 in 20 boots).

Power connections are fine, I've reseated the GPUs, I've tried isolating PCIe slots (love the DIP switch feature), I've tried changing slots around, I've tried it with and w/o SLI on the 1080s. Nothing seems to get the GTX660 to show consistently.

One curiosity, is that in the BIOS it sees the GTX660, but doesn't provide any details (except that it's running at x8 speed). I don't know if that's because it's an older card, or if it's indicative of a real problem.

At any rate, I've moved the card to my old box, and it works fine. So the card doesn't seem to be the issue.

Any thoughts as to how to further diagnose the problem? Is this a known thing with Asus GTX cards? It's really hard to search for this particular problem, as I typically am finding SLI threads.


Motherboard
Rampage V Edition 10

Processor
i7-6950X @ 3.00GHz

Memory (part number)
G.SKILL Ripjaws V 128GB DDR4 3000 (PC4 24000)

Graphics Cards
ASUS ROG GeForce GTX 1080 STRX-GTX1080-A8G-GAMING
ASUS ROG GeForce GTX 1080 STRX-GTX1080-A8G-GAMING
Asus GeForce GTX 660 GK106

Monitor
Asus MX279-8

Storage
Plextor M8Pe M.2 2280 1TB NVMe

CPU Cooler
Corsair Hydro Series H115i

Case
Zalman H1

Power Supply
Corsair AX1200i

Keyboard
DELL KS-3205

Mouse
Razor R.A.T. 9

Headset
Beyerdynamic DT 770 Pro

OS
Windows 10 Enterprise 1607

[FuryA]

Have tried using different model for 3rd graphics e.g AMD radeon to identify
make sure with other graphic card is workable

[CMDRZOD]

Did you try just one 1080 and the 660? I think what you're seeing here is a Nvidia driver limitation. The newer Win10 versions use WDDM 2.1, and I'm not sure the 660 conforms to that driver model. In the odd chance it is seen on boot by Windows, have you tested to see if CUDA works on the 660 while the 1080's are installed?

[daddyd302]

I've put together a bit of a beast for doing Photogrammetry (3D scene reconstruction with photographs). As this software is CUDA and CPU heavy, I want to continue to use my old GTX660 with the new dual GTX1080s. But when all three are installed, the GTX660 rarely shows up (maybe 1 in 20 boots).

Power connections are fine, I've reseated the GPUs, I've tried isolating PCIe slots (love the DIP switch feature), I've tried changing slots around, I've tried it with and w/o SLI on the 1080s. Nothing seems to get the GTX660 to show consistently.

One curiosity, is that in the BIOS it sees the GTX660, but doesn't provide any details (except that it's running at x8 speed). I don't know if that's because it's an older card, or if it's indicative of a real problem.

At any rate, I've moved the card to my old box, and it works fine. So the card doesn't seem to be the issue.

Any thoughts as to how to further diagnose the problem? Is this a known thing with Asus GTX cards? It's really hard to search for this particular problem, as I typically am finding SLI threads.


Motherboard
Rampage V Edition 10

Processor
i7-6950X @ 3.00GHz

Memory (part number)
G.SKILL Ripjaws V 128GB DDR4 3000 (PC4 24000)

Graphics Cards
ASUS ROG GeForce GTX 1080 STRX-GTX1080-A8G-GAMING
ASUS ROG GeForce GTX 1080 STRX-GTX1080-A8G-GAMING
Asus GeForce GTX 660 GK106

Monitor
Asus MX279-8

Storage
Plextor M8Pe M.2 2280 1TB NVMe

CPU Cooler
Corsair Hydro Series H115i

Case
Zalman H1

Power Supply
Corsair AX1200i

Keyboard
DELL KS-3205

Mouse
Razor R.A.T. 9

Headset
Beyerdynamic DT 770 Pro

OS
Windows 10 Enterprise 1607

https://www.youtube.com/watch?v=TCCEBfoUUPU

[Darkphibre]

https://www.youtube.com/watch?v=TCCEBfoUUPU

Well, I wasn't planning on throwing the 660 as an SLI with the 1080s.

NVidia supports having two SLI'd 1080s and a third graphics card as the PhysX CUDA, so my setup should work? And regardless, even without *any* SLI, the third card isn't showing up... all the time (it shows up every 10-ish boots).

[Legolas]

I think you put your 660 in the PCIEX8_4, because it shares bandwidth with Plextor M8Pe M.2 2280 1TB NVMe, that is why you losing 660.
Please use PCiEX16_3 for the third PCI card. Do not do SLI on third card also. Just SLI for the 2 1080. Also, another thing, take out the 660 card and put it back in and make sure it is installed correctly. You will get have stable 660 card.

[Darkphibre]

I think you put your 660 in the PCIEX8_4, because it shares bandwidth with Plextor M8Pe M.2 2280 1TB NVMe, that is why you losing 660.
Please use PCiEX16_3 for the third PCI card. Do not do SLI on third card also. Just SLI for the 2 1080. Also, another thing, take out the 660 card and put it back in and make sure it is installed correctly. You will get have stable 660 card.

Nope, it was in PCIEX8_3 (though I did try 4, risking a downgraded M.2 experience). It wasn't SLIed with the 1080s. Tried with 1080s SLI'd and no cards SLI'd. Finally just put it back in the old computer where it's been happy every since. :/