Dual GPU not working on x399 Taichi

parsec wrote: An HX 1200i should be enough for a TR system and two video cards. This PSU's +12V rail is capable of 100A output. If the PC is drawing over 100A from the +12V rail just booting and at idle, so much for power efficiency of TR: http://www.corsair.com/en-us/hxi-series-hx1200i-high-performance-atx-power-supply-1200-watt-80-plus-platinum-certified-psu Switching to single rail will skip the need to balance the power on the +12V rails, but just starting and running the PC should not cause that much of a power draw. 40A on a rail might be a limitation for the CPU, which could interfere with the PCIe lanes, just a thought. But the CPU here has multiple power sources/connections. I would start over by clearing the CMOS/UEFI, connect all the PSU cables to the board as required, and use one video card. Possibly starting with the 780 alone in the board. Once one card is working normally, add the other. If you've never tried the 780 by itself, that's what I would try now. I'm wondering if the VBIOS in the 780 SC is UEFI/GOP compatible. It should be if it is an EVGA video card, EVGA went to UEFI compatible VBIOS starting with the 700 series. The 1080Ti will have a UEFI/GOP compatible VBIOS. Since you use a 960 Pro NVMe SSD as the OS drive, the Windows 10 installation should be UEFI booting by default. Windows 10 installed via a USB flash drive?  "You lost me on "If i remove uninstall the 780 it then shows up as VGA adapter displaying no errors." That's the Device Manager entry, correct? I assume that is before you restarted the PC? Or does that ghost entry remain after a restart?" I wonder if this issue is related to the early Window 10 RS1 versions and the IOMMU option being enabled, not being compatible. Obviously the Windows 10 installation boots, so you are either using a Windows 10 RS2 version, or have IOMMU disabled. So the driver version is identical for both video cards? During the installation, are you prompted to select which card is the target of the installation? Or do both cards just get the driver installed? No errors from the installer during or after the driver installation process? What happens if you run the NVIDIA Control Panel software with both cards in the PC? Can you check how many PCIe lanes are being used by the 780 with that or other software? If you've used two different video cards like this in the past, is there anything you've had to do to get them working? Usually two video cards don't have a problem with the amount of memory Windows needs to deal with both cards. The UEFI option to change that is usually called Top Of Lower Usable Dram, or TOLUD, setting it to Dynamic. If and where that option is in your board's UEFI, I'm not sure, usually in the Chipset Configuration screen, but could be elsewhere with X399. Try to keep an open mind about the mother board being the problem. We see that being blamed for issues all the time, and when a new board fixes nothing, which we also see all too often, it's more than just a waste of time.

Edited by noktek - 20 Nov 2017 at 6:59am

noktek, seen this?
https://forums.evga.com/EVGA-780-SC-UEFI-post-error-m2503436.aspx
May be out of date, but please check it out.
Driver release notes: https://us.download.nvidia.com/Windows/388.31/388.31-win10-win8-win7-desktop-release-notes.pdf
VGA BIOS UEFI: https://www.techpowerup.com/vgabios/139391/evga-gtx780-3072-130514
It says "UEFI Supported: Yes".

When all else fails, open a support ticket with the Vendor.  I suspect you have a vBIOS and Driver compatibility problem.  Have you modified the CSM or IOMMU settings?  Your user manual will tell you how many lanes each socket supports.  Also try GPU-Z - here: https://www.techpowerup.com/gpuz/
For Asus Strix 1080Ti, ASUS shows a different driver: https://www.asus.com/us/Graphics-Cards/ROG-STRIX-GTX1080TI-O11G-GAMING/HelpDesk_Download/
Have fun, John.

MisterJ wrote: noktek, seen this? https://forums.evga.com/EVGA-780-SC-UEFI-post-error-m2503436.aspx

Edited by noktek - 20 Nov 2017 at 5:09pm

noktek, good, hope something gets resolved.  Seems like the 780 driver was 388.31 not 388.13.  Can you try this one.  I don't remember the vBIOS version, but GPU-Z checks UEFI.  Please keep us up.  Thanks and enjoy, John.

noktek, your 780 is UEFI/GOP compatible, in case you are still wondering, the GPU-Z screenshot confirms it.

I put a second video card in my Ryzen PC today, end of the story first:



A little story here, I did not do my usual procedure of clearing the UEFI/BIOS when installing new hardware, just connected the 650 video card and started the PC. I updated its VBIOS to UEFI/GOP compatible years ago.

The first time I started the PC, I did not have a monitor connected to the 650. Win 10 got to the loading screen circle of dots, and then froze. I shut off the PC.

I then connected a monitor to the 650, borrowing one of the three monitors I had connected to the 960. I did nothing else at all, and started the PC. I have the ASRock logo screen disabled, so instead get a few lines of text displayed only on the primary monitor, with the two digit POST code. Ryzen's POST time is long, particularly in RAID mode, so that screen is visible for almost 10 seconds. I noticed I also had the same text and POST code display on the monitor connected to the 650. This time Win 10 booted to the Desktop fine.

But the Desktop was not really active, as the little blue activity wheel instead of the mouse pointer was spinning away for at least 30 seconds. The startup/POST text on the 650's monitor disappeared finally, and my usual background picture appeared on the 650's monitor. Win 10 was obviously loading the driver for the 650, which you cannot see above, but is the same version I installed for the 960, 23.21.13.8813.

The two video cards have been running fine now for about two hours. It seems to me that the normal behavior in the situation of adding a second video card to an existing PC would be for Windows to load a driver for the card. That was simple in my case since the same driver used by the 960 could be applied to the 650, so no download of another driver was necessary, I assume. Even in the worst case situation, say of a PC not connected to the Internet, without a compatible driver for the second card available, the generic Windows video driver that would be installed during a new Windows installation would be used, and installed on the 780. Do you agree?

Just to confirm for me, the GPU-Z screenshot was done on another PC, not on the X399 PC, correct? I only ask because I see it shows PCIe 2.0 as the interface. Not that it should make a difference.

The highest level question is, why wasn't a driver installed for the 780 video card? We don't have the same information from happyferret since he is not using Windows. But it is interesting (and telling) that he seems to have the same problem. How can we know specifically if it is the board's UEFI/BIOS that is the problem, not that I'm dismissing that. It is all to easy for another manufacture to pass off problems on the board's UEFI/BIOS, but it seems to be heading in that direction.

I have nothing new to suggest as a fix. I suppose an inadequate PSU problem with both users at 1200W seems improbable, but who knows? While my two video cards are not power hungry, I'm using a Seasonic 660W Gold PSU in my Ryzen X370/1700X PC. Can you run a monitoring program to check the PSU rails, to see if your +12V rail seems to be drooping below 12V, possibly as an indication of a power issue? That is shown in the H/W Monitoring screen in the UEFI.

I cannot find a TOLUD option in your board's manual, but as I said the manual is not up to date with all the UEFI updates. In the Advanced\AMD PBS screen there is the PCIe x16 Switch option, and the Promontory PCIe Switch option. What those options do, I don't know, but their default settings should allow multiple video cards, if these options were related to that. They are worth checking just in case.

One experiment for you, in the Boot screen in the UEFI, find the CSM option. Click on it to see its sub-options. Find the Launch Video OpROM Policy option, and set it to UEFI only. Then Save and Exit, boot into Windows, and see what happens. If you cannot boot after changing this option, you'll need to do a UEFI/CMOS clear to restore sanity, and that will work I promise.