Msi Z390 A PRO with 11 gpus and not accepting 12


I’m currently running a rig with a msi z390 a pro successfully with 11 gpus

The pci slot mapping are :
1: PCIx16 → splitter 1 to 4 : 4 gpus (4xriser)
2: PCHx1 → 1 gpu (riser)
3: PCHx1 → 1 gpu (riser)
4: PCHx4 → splitter 1 to 4 : 4 gpus (4xriser)
5: PCHx1 → 1 gpu (riser)
6: PCHx1 → empty

My bios is set up and i disabled audio + serial + parallel, video set to IGD and screen on motherboard DVI port.

Unfortunately when i plug my card #12 it does not work (i’m not even seeing the bios … i got a black screen)

Did some have managed to make it work with more than 11 gpus and how ? I believe I ran out of pci lanes (This topic is hard to fully understand and gave me headache about pci / pch , cpu and chipset max lanes , why the 1 to 4 spliter has a x1 form factor -will sound logical it have x4 form factor as it split x4 to four x1 lanes …).

Anyway if we have some expert on the topic I would like to know if trying to disable usb in the bios could free some pci lanes (this means I should buy a ps2 keyboard and migrate my hiveos usb dongle to a sata ssd) ? other option is to disable sata but it seems not possible on this motherboard (no option in bios) … btw i was unable to find a block diagram to know if my m2 x4 port (currently unused) is PCI or PCH -this could be a third option to add gpus-

Thanks for any advise on that :slight_smile:


and here we go, you have successfully connect 11 GPU with msi z390 a pro, some user / people were having a problem connect to 6 GPU with this motherboard


try to set IGD to external GPU Display to free up some PCIE-Lanes

I have same Issue, was able to connect 11 GPUs tried different setting but 12th won’t connect, using HiveOs on MSI Z390-A PRO, I have same problem with MSI Z590 A-PRO only 11GPUs works after connecting 12th it will not boot to bios or to HiveOs, Z390 white LED will lid as no graphics available nothing different on Z590 just wont go to HiveOs or bios. If you have any luck please post that. I will keep playing around as well.

Hi . what CPU use you for this configuration?? thank you

I Have the Z-390 A-Pro Board
an by me works it fine with 11 GPU´s
I Have the I5 9400F
4x 6600XT 7x 6600

333 Mh/s 564 Watt

Hi thank you.
Where do you connect PCB 1pcie x4 USB?? In pcie x1 or x16

Thank you

on PCI_E1 are the first GPU RX6600 direct on the Board for Monitoring
PCI_E2 empty “the GPU from PCI_E1 are over it”
PCI_E3 the First 1 to 4 PCI Riser Adapter
PCI_E4 the second 1 to 4 PCI Riser Adapter
PCI_E5 Riser direct to the GPU
PCI_E6 Riser direct to the GPU

i hope i can Help You