Resolved Question

PC won’t post with second gpu installed

Dec 31, 2017 3:00PM PST

I just upgraded my PC with a fresh Windows 10. Initially I started with 1 GPU installed to get everything up and running. When I installed the second GPU my system now will not boot up - won't post. When I take the 2nd GPU out the system boots fine. I think I should have enough power - what are you all's thoughts.

Corsair 760T Case with no additional fans added
Ryzen 5 1600x
Asus Strix x370-F Mobo
Cooler Master Masterliquid Lite 120
Samsung 960 EVO M.2
Single DVDRW
G.Skill Ripjaws V 16GB 2 x 8GB DDR4-3200 PC4-25600 CL16 Dual Channel Desktop Memory Kit
1 - ASUS GeForce GTX 1080 ROG Strix 8GB GDDR5X Video Card w/ Aura RGB Lighting
1 - ASUS GeForce GTX 1080 TURBO-GTX1080-8G 8GB 256-Bit GDDR5X PCI Express 3.0 HDCP Ready SLI Support Video Card
EVGA SuperNOVA 850 G3 850 Watt 80 Plus Gold Modular ATX Power Supply

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Clarification Request
Many Ryzen boards have issues.
Dec 31, 2017 3:07PM PST

Just go ahead and be sure the BIOS is their latest and the maker says they support more than one GPU.

But a 1080 under load has been spotted at 350 Watts so that 700 of your 850W PSU without more headroom for the rest of the PC.

Still usually fine to boot, you should see random BSODs under load but for now, let's hear what BIOS it's at and if the motherboard maker tells you it supports this configuration.

-> Be sure to test that each card works. A few folk found out they had a dead card.

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Bios up to date
Dec 31, 2017 3:18PM PST

Thanks for that info. I’ve made sure the bios are up to date and have also tested each card. Either card works on its own in either pcie 16-1 or pcie 16-2. I plan on calling Asus in Tuesday when they open up but according to the manual it will support sli.

I thought it might be something to do with the m.2 taking up too many lanes but when I tested with another ssd connected to a SATA plug it did the same thing.

I’m truly wondering if the psu isn’t powerful enough although the cards worked together in an older build I had with an fx 8 core processor.

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That was with the same psu
Dec 31, 2017 3:18PM PST

I forgot to mention that was using the same psu

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Wait? Old PSU?
Dec 31, 2017 3:23PM PST

PSUs lose capacity with age. It's just a thing you learn over time. Just how old is this PSU?

Can you free up any Watts? Unplug the ODD or other things?

The total system Watts should exceed the 850 even if it was new but as they age, they can develop boot issues with high Watt devices.

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It was in my old system
Dec 31, 2017 3:29PM PST

I had just replaced the psu and then the wife surprised me and let me continue to build a whole new rig. So the psu is only 2 weeks old.

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That's not old.
Dec 31, 2017 3:37PM PST

But I still think you may see issues under load.

Booting usually isn't where a new PSU should be an issue but still is there anything odd about the rig? 20 hard drives, dozens of fans, BitCoin mining? Anything that's not in a run of the mill PC?

Remember the 1080 is usually more than ample to run UHD gaming but SLI? Usually not done due to headaches.

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Yea it’s a mining/gaming rig
Dec 31, 2017 3:43PM PST

I only have 1 m.2 ssd and 1 1tb hdd installed. Only added 1 optical drive and no additional fans yet.

It’s just really odd that it worked in my old setup but when I put it in the new rig it doesn’t work. I was running 2 1080s off that psu for a week or two with no problem. The cpu/mobo is the biggest difference from how I had them situated before.

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Then to me it's the motherboard.
Dec 31, 2017 4:08PM PST

There are boards all about Ryzen and odd issues like this. I won't go looking for those but a call to the motherboard maker should confirm it. If not the GPU maker (not Nvidia but the card maker) make have them spill the beans.

In BitCoin mining they don't use SLI but just tap the GPU computational power. For gaming, still rarely SLI since a 1080 would be fine for one UHD display. I can only guess the second GPU is for a second display.

If the GPU is just for mining and you can't change the motherboard, maybe one of those riser card setups like

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What’s nice is they’re all Asus
Dec 31, 2017 4:35PM PST

So one call should be able to answer the mobo or gpu question.

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I'm going to ask a favor.
Dec 31, 2017 4:45PM PST

Remember I don't have access to a rig like yours. If you could be so kind, hit back with that they say here. Folk love to read what it was and I learn more as folk share their experiences.

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Yes Please
Dec 31, 2017 4:53PM PST

I'm reading this thread and am wondering what the outcome will be so please let us know .....

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Of course
Dec 31, 2017 4:59PM PST

Yea I will post the solution once I have it figured out.

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Clarification Request
may we assume
Dec 31, 2017 4:49PM PST loaded driver files for both video cards? Were they the same driver files? Was there an option to install the second set of driver files to a different folder? I know in Linux it's problem trying to run two video cards that use the same driver files without the second card having the second set in a different folder and sometimes renamed and then assigned as a "mod" to the kernel. Windows might have the same problem. Easiest fix is to use video cards that are from different makers using different driver files. I see SLI, have you tried using that method?

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They are the same
Dec 31, 2017 5:01PM PST

What’s nice is they both use the same driver but yes they are up to date. I made sure they both said up to date when installed separately. The system will work with either of them installed on its own.

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For some reason
Dec 31, 2017 6:21PM PST

the windows you are currently using isn't differentiating between them. Whether it's the same situation I've seen in Linux, can't say for sure, but tossed that out there, as a possibility. One set of drivers for two cards, I can see that being a problem. Do you have any other video card you can swap in for a test, to see if the same thing happens, preferably one that isn't the same as those, or use the same driver files? I think you may need to change some configuration file manually to differentiate from them, maybe even the .inf file, by changing the identity in it by a one up number perhaps, so when it's installed windows will look on it as two different cards. So far, can't even check device manager to see if it identifies two separate cards installed.

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Since they can't get to the BIOS or boot
Dec 31, 2017 6:25PM PST

I doubt this is a Windows issue.

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a good point!
Dec 31, 2017 6:34PM PST
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I’ve spent considerable time in bios
Dec 31, 2017 6:47PM PST

Looked over multiple pcie settings and all appear to be good to go.

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try a different second video card
Dec 31, 2017 7:03PM PST

see if that makes a difference. Borrow one, use an old PCI if around, whatever. See what happens and then maybe see what's in the BIOS if it works. It might give clue on why twin video cards won't work.

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auxiliary power to both cards?
Dec 31, 2017 7:04PM PST

Or just one, or both only in slots, no power plug from PSU to them? I'm wondering if it's trying to pull too much power from the PCI3 bus.

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(NT) meant PCIe bus
Dec 31, 2017 7:05PM PST
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Dedicated psu connection
Dec 31, 2017 7:08PM PST

Each card has its own dedicated plug from the psu.

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I'm out of ideas for now
Dec 31, 2017 7:12PM PST

I will think on it more, maybe tomorrow I'll have some new idea. I'm guessing when you get the black screen, you also get a "No Signal" message from the monitor? The computer stays powered on?

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Monitor stays in sleep mode
Dec 31, 2017 8:00PM PST

The monitor goes to sleep mode when I turn the pc off. Typically it will power on as soon as power is sent to the gpu but with the 2 installed I get nothing to wake the monitor up.

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may we assume
Jan 1, 2018 12:56AM PST

you booted with one gpu, went into windows, and set it up for dual monitor?

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Here's some helpful articles
Jan 1, 2018 8:35AM PST

One of the items that stood out was the Nvidia requirement to have each card with different clocking frequencies, perhaps so they could be distinguished from each other by the driver files? Similar to my comments about similar problems in linux systems. The other I mentioned was SLI or AMD calls theirs "Crossfire", requiring them to run "in tandem".

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Suspected mobo
Jan 3, 2018 9:01AM PST

Had to go back to work so I dropped it off at micro center to let them figure it out. But it’s suspected the mobo is bad.

Best Answer

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Suspected mobo
Jan 3, 2018 8:57AM PST

Had to go back to work so I dropped it off at micro center to let them figure it out. But it’s suspected the mobo is bad.

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Dec 31, 2017 5:33PM PST

How do you know it won't post?

Do you mean it won't boot the OS?

That's 2 different areas.

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Black screen
Dec 31, 2017 6:09PM PST

I don’t make it to the bios. My monitor doesn’t even recognize a video signal to turn on from sleep mode.

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