Z390-A Pro Won't Boot with 5 GPUs

danprice30151502d7

New member
Joined
Oct 8, 2020
Messages
5
Hi. System works fine with 4 GPUs, but installing 5th, known good GPU of same type, with known good riser, etc., and boot stops with lighted VGA Easy Debug LED. I've set BIOS (current) to usual suggestions, Gen2/3, Above 4G RAM (system has 16), etc. Anybody have more than 4 cards running on this board? Any advice appreciated!
 

Svet

Well-known member
Administrator
Joined
Nov 20, 2003
Messages
77,078
What BIOS version board is using?
 

danprice30151502d7

New member
Joined
Oct 8, 2020
Messages
5
Hey, Svet, thanks for asking! I got 5 cards to work after switching from legacy to UEFI boot mode in bios settings, I think that was the only issue all along. Have a great day!
 

Svet

Well-known member
Administrator
Joined
Nov 20, 2003
Messages
77,078
Glad you figured, thanks for the update.
 

Batman

New member
Joined
Feb 20, 2021
Messages
8
Well just bought one today and connected 5 GPUs. Bios won't boot and "VGA LED" is fixed on.
Works ok with whichever combination of 4 cards\psu\risers, but never with 5.
 

Batman

New member
Joined
Feb 20, 2021
Messages
8
Ok, it works now.
Solution is to fix the PCIe speed to "Gen2" instead of "Auto" or "Gen1"

Cheers
 

runyanm155802dc

New member
Joined
Mar 4, 2021
Messages
16
I really wish your solutions worked for me too. I've done everything and can't get it to detect a 5th video card.
Set PCIE speed to Gen 2 and tried changing boot mode to UEFI, didnt work
I've tried BIOS versions 7B98v1D and 7B98v1C and neither helped fix my issue.
 

Batman

New member
Joined
Feb 20, 2021
Messages
8
I really wish your solutions worked for me too. I've done everything and can't get it to detect a 5th video card.
Set PCIE speed to Gen 2 and tried changing boot mode to UEFI, didnt work
I've tried BIOS versions 7B98v1D and 7B98v1C and neither helped fix my issue.
Hello,

It does work, although really there's some kind of problem there. Maybe physical connection issues on the risers? Check riser's usb3 cables, power source, and try booting other OS
 

Batman

New member
Joined
Feb 20, 2021
Messages
8
Did you connect the additional PCIe 6 pin input on the motherboard? the board needs that extra input from the PSU, to be able to power up correctly every PCIe slot.
 

runyanm155802dc

New member
Joined
Mar 4, 2021
Messages
16
Did you connect the additional PCIe 6 pin input on the motherboard? the board needs that extra input from the PSU, to be able to power up correctly every PCIe slot.
I haven't done this yet. What kind of cable did you use? A 6 pin from one of the two 6+2 pins from a VGA PSU cable?
 

Batman

New member
Joined
Feb 20, 2021
Messages
8
I haven't done this yet. What kind of cable did you use? A 6 pin from one of the two 6+2 pins from a VGA PSU cable?
That's your problem then :)

Yes, use the 6+2 cable, and connect only the 6pin part.

Tell me if It worked.

cheers
 

dcollins2154002de

New member
Joined
Mar 6, 2021
Messages
5
Hi, I am having the same exact problem, i have reflashed the bios changed all the settings mentioned above swaped cards in and out moved cards across pcie slots, reinstalled windows and changed the power supply. Any ideas on how to fix this? I have 4 asus 1660 supers and 1 zotac 1660 ti. 4 4 cards or less works fine. Thanks for any help
 

runyanm155802dc

New member
Joined
Mar 4, 2021
Messages
16
That's your problem then :)

Yes, use the 6+2 cable, and connect only the 6pin part.

Tell me if It worked.

cheers
Still didn't work even after plugging into the 6pin, I don't know what the hell I'm supposed to do at this point, this is so dumb.
 

dcollins2154002de

New member
Joined
Mar 6, 2021
Messages
5
I got mine to work this morning. Go to the bios in advanced setting . Then go to the windows settings and change it to uefi. Apparently this setting is in both the boot heading and the windows heading. Took me 6 hours to figure this out. Hope it helps
 

runyanm155802dc

New member
Joined
Mar 4, 2021
Messages
16
I got mine to work this morning. Go to the bios in advanced setting . Then go to the windows settings and change it to uefi. Apparently this setting is in both the boot heading and the windows heading. Took me 6 hours to figure this out. Hope it helps
if I change this setting, it gives me a warning before that it cant access GOP and demands that I either reset defaults and continue, or go to setup
 

dcollins2154002de

New member
Joined
Mar 6, 2021
Messages
5
I didn't get that. But I did change the boot to uefi. Gen 2 on the pcie and the mining setting(4g) Disabled every device I could. Used the 6 pin power connector. Enabled the on-board video to work with the gpus . And the changed the windows uefi setting. The last step is what worked
 

runyanm155802dc

New member
Joined
Mar 4, 2021
Messages
16
I'm starting to think I know why this is working for some people when they turn on UEFI Windows configuration and not for me.
I'm going to guess you all installed CPU's that came with integrated graphics.
Me, assuming I would be okay with a CPU that did not have integrated graphics, installed one. I think it's working for you folks because it never brings up the GOP menu since you all have CPUs with integrated graphics and since mine doesnt, it brings up that GOP warning error interstitial every time.
 
Top