Topic: Motherboard Z97 Extreme4 issue - debug error 55 (Read 285 times)

Hello,

Sorry for the late reply. Haven't managed to fix the issue, started using 5 GPU per motherboard and that's it. Somebody who is using the same motherboard has RX570 and he managed to get 6 of them work on single motherboard. Might be issue with nvidia + that motheboard but can't be sure.

Have you managed maybe to get it working?

Hello, i have exactly the same issue now.
Did you managed something to get all 6 GPU working? Thank you.

Hello BTCT members,

recently built a mining rig of the following components:
- 6x GTX 1060 3GB with USB powered risers
- 4GB Kingston RAM supported by motherboard
- XFX 850W PSU (even tried running the rig with 2x850W)
- Intel G1840 CPU
- SanDisk 120GB SSD
- OS used: Linux nvOC by zerofull (https://bitcointalksearch.org/topic/os-nvoc-easy-to-use-linux-nvidia-mining-1854250)
- NVIDIA drivers version: 378.13

On the rig, 5 GPU work correctly with no problems, but when I try to plug in the sixth GPU, on boot the motherboard displays debug error code 55 (Memory not installed) on the LED screen and the only way to start again is to reset BIOS.

I've tried the following:
- changing RAM slots A1,A2,B1,B2
- adding more RAM up to 16GB
- security device support off
- sound off
- serial off
- switching pcie slots 2 and 5 to Gen1 and Gen2
- plugging in sixth GPU after BIOS goes through
- switching from onboard graphics to PCIE and using 6 GPU

If the graphics is set to PCIE and 6 GPU are plugged in - error 55 - solution: reset BIOS.
If the graphics is set to PCIE and 5 GPU are plugged in - goes through and starts mining.
If the graphics is set to onboard and 6 GPU are plugged in - error 55 - solution: reset BIOS.
If the graphics is set to onboard and 5 GPU are plugged in - goes through and starts mining.

Tried changing GPU, riser, PSU, RAM, CPU... well everything.

Read online and some people suggested to set TOLUD or enable Above 4G decoding, but I don't have those options in BIOS.

Spent hours debugging, so any help appreciated.

Thank You