Asus Prime H470 Plus - Problem connecting 5 GPUs

[badjoras]

Hello fellow miners, anyone here with a Asus Prime H470 Plus that managed to add more than 4 gpus, could you share your Bios settings?

I have some weird stuff going on, I already applied the most common Bios settings found on the web, however as soon as I add the 5th gpu, the power starts, but it doesn’t boot. I changed risers, PCI ports, gpus, adding one at a time, well almost everything, but no success, the behavior is always the same as soon as I add the 5th one.

And it gets weird, because if I connect a HDMI to the motherboard, I can only start with 3 gpus, as if the CPU motherboard counts as a limit…

I have a Gold G6500 CPU, 120GB SSD and 8BG RAM.

Thanks

[nanial]

Make sure to do the following

ASUS Prime H470 Plus BIOS Settings:

• Disable all ASPM (Active State Power Management) options
• VT-d = Disabled
• Above 4G Decoding = Enabled (Default is False)
• DVMT Pre-Allocated = 96M (Default is 64)
• PEG Port Configuration → PCIEX16_1 Link Speed = Gen2
• PCI Express Configuration → PCIe Speed = Gen2
• CSM (Compatibility Support Module) → Launch CSM = Disabled (Not Required)
• Boot Option #1 = ssd or flash disk

[badjoras]

Thanks a lot for the reply, I already had those settings and tried others, however just one thing solved my problem: flashing the BIOS. After that I got 6 cards working.

The board came already with the latest version (1602 from 2021/01/15) so I wasn’t bothered with that, but after all seems that something was not working well with the version from the factory.

Anyone out there that might have the same issue try flashing the BIOS even if already have the same version and then apply the settings above.

[gustavoboy106]

Have you tried to add more GPUs with the M2 slot? You could be able to have 7 GPUs in total I guess. Have you tried PCI 1 to 4 splitters?

I am wondering if using the 2 ports of PCIe x16 to use PCIe splitter 4 to 1, so a total 8 GPUS + M2 port and 4 more gpus in the 3 single PCI ports to have a total of 13 GPUs

@badjoras