Unable to setup 4th GPU in rig[SOLVED]

[DBAGI]

Hi,
I have a rig with 3 GPUs:
2xAsus Dual RX580(with modded bios)
1xSapphire Pulse RX570(no bios modification)
Motherboard: Asus H81m-pro with 4GB of RAM.
I'm trying to add one more GPU(Sapphire RX570) but with no luck. I checked all of the risers-OK, all of GPUs are working since I tried them one by one. My OS is Win10 and I'm using latest blockchain drivers from AMD. So, I tried DDU and clean install but no change, 4th GPU isn't showing up in device manager. Sometimes fans of this card starts to spin at maximum speed when I power on the rig and stays like that until I do windows reboot.
I checked bios settings but there's nothing particular to indicate this issue.
Only thing left is to reinstall windows but I think doing that would not fix the problem.
Does anyone have any idea what can I do to fix this problem?
Regards.

[timiddude]

got this problem before and it turned out to be faulty riser. exact same symptoms (fans not controlled and GPU not detected).

what's weird is that the risers all worked when I tried them one by one. but when I switched around, a gpu with that one riser always get problem.

[DBAGI]

Hi,
I tried several risers but still the same. This happens only on 4th GPU connected to pciex1_3 slot and what is interesting that if there's a 3 GPUs, no matter in which slot I connect them, they work.
Thanks.

[umine]

Hi,
I have a rig with 3 GPUs:
2xAsus Dual RX580(with modded bios)
1xSapphire Pulse RX570(no bios modification)
Motherboard: Asus H81m-pro with 4GB of RAM.
I'm trying to add one more GPU(Sapphire RX570) but with no luck. I checked all of the risers-OK, all of GPUs are working since I tried them one by one. My OS is Win10 and I'm using latest blockchain drivers from AMD. So, I tried DDU and clean install but no change, 4th GPU isn't showing up in device manager. Sometimes fans of this card starts to spin at maximum speed when I power on the rig and stays like that until I do windows reboot.
I checked bios settings but there's nothing particular to indicate this issue.
Only thing left is to reinstall windows but I think doing that would not fix the problem.
Does anyone have any idea what can I do to fix this problem?
Regards.

Does your OS not detect 4GPU at all or it detect it as unknown device or with any error code? Did you update MoBo BIOS to the latest settings? I've MSI MoBo with the same chipset and it works well with 4 GPUs both Nvidia and AMD

[DBAGI]

Hi,
OS is recognizing only 3 of GPUs, there is no 4th in device manager at all(like as unknown or device with problem).
My MoBo bios version is 2205 as on Asus support page. Is there something in bios settings that I'm missing, some particular settings to apply?
Thanks.

[andydis]

What PSU do you have?

its possible its not getting enough power

or a faulty RISER

[DBAGI]

Hi,
the PSU is new EVGA SuperNOVA 850 G2. I tried to isolate the riser but they all working when 3 GPUs are connected. I tried connecting GPUs one by one (starting from slot pciex16_1) and windows detects and installs drivers without problem. But when I connect 4th card into pciex1_3 slot, windows boots up not showing that GPU(fan is spinning like on other 3).
Thanks.

[DBAGI]

Finally found solution. I unplugged one rx570 and left two remaining rx580 connected. After windows booted up I uninstalled(deleted)  drivers for 2 rx580 through device manager not DDU. Then powered off pc, plugged 2 rx570 and powered up. All card showed in device manager as basic display adapters, installed blockchain drivers and ati patcher. After that I rebooted pc and mining is on ⚒ 
Best regards.