BTC S37 - 12 GPU Issue

[Northernlights]

I am mining since over 6 months and I have an issue recently that I could not solve by myself. Maybe someone experienced something similar and could give me a hint to solve it

I have a BTC37S motherboard. Until now I had 11 GPU running smoothly on this motherboard. 6x3070, 3x3060TI, 1x3080 and 1 x1660TI, all non LHR. I use 4 onboard pcie slot, 2 risers to single card and 2 pci splitter to the other cards. 2 HP 1200W PSUS are directly powering the cards using 6pin to 2x8pin connectors. Motherboard 1st PCI-E is connected to PSU also. It worked perfectly with 11GPU,

Recently I added an 12th GPU (Zotac non LHR 3070) and the hashrate and power usage of all my cards dropped by around (15%-20%) (see picture attached). On 3070/3060TI I was getting > 62MH before and now it doesn’t go past 52MH

I suspect I reached a limit either linked somehow to PCI-E lane bandwidth or some other hardware limitation. I tried to have a look at the bios settings to see if something could be changed but I am not sure where to look.

Any idea or hint is welcome

Thank you

[VietnamAK47]

Update driver 470.63.01 running phoenixminer

[SaintCowboy]

I have that same board and let me tell you I’m surprised you have been able to add 11 without seeing a major drop because the amount of lanes on those boards is not actually 16x. Your board probably doesn’t have enough lanes to transfer that data and such efficiently. That is one of the only problems with that board.

[tommys]

@Northernlights out of curiousity, are you using ATX power supply or Server? Cheers.