Mining rig 4th gpu not working

[maxgpu8787]

I have a gigabyte z170 gaming 5 motherboard and 4 msi 3rd 570 gpus. I'm running the latest bios and drivers on the motherboard and gpus. The cards all have stock bios. I have the first 3 cards plugged into the 1st 3 slots of the motherboard through PCI risers, but when I plug the 4th card I go down to just 2 cards being recognized, cards 1 and 2. If I plug card 4 into the 5th slot then card 3 isn't recognized. Any idea what the issue is I cannot seem to get all 4 cards recognized at the same time no matter what slots I have them pligged into. Amy help is appreciated

 

[reedo_43]

I am no expert on this by any means, but do you have enough pcie lane on your cpu?

 

[maxgpu8787]

I have an G3900 so it should handle up to 6 gpus no problem

 

[toshibitsu]

Apparently, that motherboard has issues with getting more then 3 video cards working at the same time. Doing a google search, found various other forums/threads of people with the same board having the same/similar issue.

 

[reedo_43]

https://ark.intel.com/products/90741/Intel-Celeron-Processor-G3900-2M-Cache-2_80-GHz

 

[toshibitsu]

https://ark.intel.com/products/90741/Intel-Celeron-Processor-G3900-2M-Cache-2_80-GHz

and there's the magic 3 again. looks like he'll have to replace the cpu and possibly the motherboard.

 

[maxgpu8787]

I think it is the motherboard I have a few friends with the same cpu motherboard setups that have no issues.