Question Can't see the BIOS screen when GPU's are in SLI

[Star Trek Steve]

My PC specs:
OS: Windows home 10 Version 10.0.17134 Build 17134
Mobo: MSI Z370 Gaming M5
CPU: Intel i7 8086k
CPU Cooler: Corsair Liquid Cooler h100-v2_QSG
RAM: Corsair Vengeance LPX 2x32 GB 3000 MHz C15 DDR4
PSU: Corsair RMx 750
GPU: 2x NVIDIA 1080 in SLI mode
SSD: Samsung 970 EVO 1TB
HDD: WD 4TB Black
Blu-ray Drive: LG BH12
Case: Enermax Ostrog ECA 3380 series
Case Coolers: 1x120mm Back-side fan (exhaust), 2x120mm Front-side fans (intake), 1x120mm Bottom fan (intake)
Monitors: 22" Samsung S22B310B HDMI input, LG 27UK600 Display Port input

After I added the second GPU when I launch my PC with my GPUs installed in SLI, I don't see the BIOS screen, meaning it boots straight to Windows.
After some testing I figured out that the BIOS screen, while not being displayed, is active while my monitors are black. I have to reset the BIOS in order for it to display. Then when I reboot it again goes straight to the Windows OS. I know the BIOS is posting because of the beeps it makes. I have disabled FAST boot option in the BIOS but it still will not display.
If I take the cards out of SLi and put the Samsung monitor on card 2 HDMI input and leave the LG monitor on card 1 Display Port the BIOS screen will display when I hit the delete key on a reboot.

 

[SgtScream]

Is your motherboard on the latest bios revision?

 

[Star Trek Steve]

Yes, I flashed it a month before I installed the second GPU.

 

[SgtScream]

It is most likely showing the bios screen on the other card then switches to the one with the monitors plugged in once windows boots up. You can test it by plugging a monitor into the other card and the boot the system.

 

[Calvin7]

To access your BIOS on a Windows 10 PC, follow these steps.

1. Navigate to settings. ...
2. Select Update & security.
3. Select Recovery from the left menu.
4. Click Restart Now under Advanced startup. ...
5. Click Troubleshoot.
6. Click Advanced options.
7. Select UEFI Firmware Settings. ...
8. Click Restart.

 

[Star Trek Steve]

I did as SgtScream suggested and plugged a 3rd monitor into card number 2. The BIOS displays on the 3rd monitor. Because the cards are in SLI with the other two monitors are on card 1 the 3rd display stays dark once Windows is booted. I have to take the cards out of SLI to get all three displays to work in Windows. This defeats the purpose of having 2 cards so I could use SLI. Is there any other solution to have the BIOS display short of taking the cards out of SLI whenever I need to do a BIOS change?

 

[SgtScream]

You should be able to use all 3 monitors in sli. Excuse me if i'm not understanding you correctly, but what happens if you plug all three monitors into the card that displays the bios splash screen on boot. Are you able to do that and still use all three monitors in windows?

 

[Star Trek Steve]

Yes, all three monitors will display if they are on the same card in SLI. The BIOS will display only if I put one monitor on card number 2.

 

[SgtScream]

And if you plug all three monitors on card number 2 then you no longer see the splash screen on boot?

 

[Star Trek Steve]

That's correct. No Splash screen using all three monitors on card 2.

 

[SgtScream]

I'm starting to think it's the graphics card. Does the same thing happen on graphics card 1? What's the make and manufacturer?

 

[Star Trek Steve]

They are both NVIDIA 1080 GTX cards. I tried putting both monitors on card #2. Both Cards are in PCIe 3.0 x16 slots. Card 1 is in PCI E1 closest to the CPU and card 2 in the next PCIe 3.0 x16 slot over. I moved both monitors over to card number 2 and now the BIOS will display on my primary monitor the LG 27UK600 on a Display Port input. Issue solved. Don't have any idea why this would make a difference having both monitors on card 2 in SLI (BIOS Displays) vs both monitors on card 1 in SLI (BIOS does not display). Go figure.