dropping gpu cards

[itlbtu2]

I'm about to lose my shit dealing with one of my rigs...I am running older equipment. EVGA Z87 FTW mobo, 2x EVGA 750G PSU's 4x R9 270X.   also using simple mining for right now.  One identical rig is running perfectly. however I have another that will start fine showing 4 gpu's and producing shares.  Approximately 1-2 minutes later it will drop to only GPU 0 (In a pci-e slot) and GPU 3 (on a usb riser) the other two cards (one connected to pci-e and one on a riser) stop mining.  I have a hard time thinking that it is a power issue due to the dropped cards being on different PSU's, and I have tried different risers without any change.  one or two minutes and they drop......Is my mobo bad?
  Any help is greatly appreciated.

[ZenFr]

I had the same issue a long time ago...
After a long time of tests, the problem was the BIOS of the MOBO : all was working fine, but the Two BIOS (MOBO and GPUs) was interact to tell the max power limit of the PSU was less than the max power limit of the GPUs (and not the satndard limit of the GPUs).

[itlbtu2]

how did you fix the problem?

[ZenFr]

how did you fix the problem?

I Changed my RIGs and put less max power GPUs in this motherboard.
After that I changed again, and this time all worked fine : that was allways some 1070s GPUs but from an other manufacturer, so other GPU BIOS and this time GPU BIOS and motherboard BIOS worked fine together.

[itlbtu2]

I Changed my RIGs and put less max power GPUs in this motherboard.
After that I changed again, and this time all worked fine : that was allways some 1070s GPUs but from an other manufacturer, so other GPU BIOS and this time GPU BIOS and motherboard BIOS worked fine together.

I just upgraded my bios a couple weeks ago, could I have gotten a bad flash? should I re-flash it or maybe downgrade?

[ZenFr]

I Changed my RIGs and put less max power GPUs in this motherboard.
After that I changed again, and this time all worked fine : that was allways some 1070s GPUs but from an other manufacturer, so other GPU BIOS and this time GPU BIOS and motherboard BIOS worked fine together.

I just upgraded my bios a couple weeks ago, could I have gotten a bad flash? should I re-flash it or maybe downgrade?

You can try this, yes.
But if it's don't work, I see only one of these solutions :
 - unplug 1 GPU
 - upgrade your PSU
 - change GPU manufacturer

[SUDARMONO]

I prefer to replace my equipment that has started problematic, let all can quickly run normally and get maximum results