Can't get 5GPU with Asus Prime z270-p (FIXED)

[Millime]

Hello !

I actually have a asus prime z270-p and I'm not able to make it work with 5 or + gpus.
When I connect the fifth card, I see the Mobo logo but screen stays black after.
I'm running on w10, this is my third asus prime z270-p and I didnt had any issues with the two others.

The bios is updated to the latest version
-4G enabled
-Pci speed set to GEN 1 (tried with GEN2 but doesnt work)
-Hd audio controller is turn off
-Fast boot disabled

Also, When i disconect the fifth card and reboot, w10 is showing correctly and the drivers are working

My monitor is connected via the hdmi of the mobo.

Thank you!

EDIT: I've tried different pcie port and it doesnt make a difference, I can get 4 gpus working with any pcie port order used.

[mshordja]

Every GPU testing one by one are working?
-What drivers are you using?
-PCI Gen1 to all 3 points?
-Power supply?
I had the version H270 from asus and no problem with 5 or 6 cards.

[ylpkm2]

try setting all pcie slots speeds to gen 2. (3 locations to change this)
disable the lightning port.
double check the riser cable/swap the cable for another.
try skipping a pcie lane with the riser.

[mshordja]

try setting all pcie slots speeds to gen 2. (3 locations to change this)
disable the lightning port.
double check the riser cable/swap the cable for another.
try skipping a pcie lane with the riser.

if you have done all this, than i think is a driver problem , try to uninstall and install fresh drivers , blockchain ati drivers,

[Millime]

Every GPU testing one by one are working?
-What drivers are you using?
-PCI Gen1 to all 3 points?
-Power supply?
I had the version H270 from asus and no problem with 5 or 6 cards.

-Tested individually, they all work
-Risers/cables tested

I had all 3 options set to GEN1, switched them to GEN2, switched them back to GEN1 and now it's working with 6 gpus....

Wow... What an annoying problem