Really weird problem with using multiple GPU's on mining rig

eternalbeat

Prominent
Jun 21, 2017
3
0
510
Hey there.

Specs are:
MSI Z170A mobo
6x ASUS GTX 1080
PSU Lepa G1600
Intel i3 CPU
SSD HD
Samsung Monitor
Windows 10 1703

I'm having a weird issue and hoping you folks can help me. This is a brand new build today, just getting it setup, and my first ever mining rig.

I'm having problems with the display. The monitor is plugged into GPU #1 using HDMI port.

If I have 1 GPU installed: everything works fine.
2 GPU's installed: everything works fine.
3 GPU's installed: Screen remains blank during boot, cannot see the BIOS screen, monitor just blinks like its waiting for a signal. However, if i wait long enough it will boot to windows just fine.
4 GPU's installed: same as above. Can't see boot screen/BIOS, but when windows finishes loading, can use windows.
5 GPU's installed: Now I can't see when windows loads either, or the BIOS. All 5 cards light up with fans going. Just no display whatsoever.

it's weird that the functionality deteriorates with each additional card I add.

Haven't tried 6 yet because one of my riser adapters is a dud. However I can't even function with 5 as of now.

Any ideas what I can do here? Thanks in advance for any troubleshooting.