My rig has been working fine with three GPUs, but when I try to add a fourth, my machine keeps giving me the BSOD when I start mining. I suspect it has something to do not having enough power, but I'm not sure what to do about it.
I have a Seasonic 850W Gold PSU. I'm able to run with three GTX 1060 6GB cards, or with two of those and one RX 580 8 GB. The PSU has three PCI-E cables, each of which one plug that goes into the PSU and two 6/8-prong connectors for GPUs. If I plug each connector into a separate card, it works fine (whether or not that card is on a riser, so the riser doesn't seem to be the issue). But to go beyond three cards, I have to use both of the plugs for separate cards, and once I do that, it becomes unstable.
I thought it might be that the PSU couldn't supply enough current on one connector, but I found that even if I reduce the power target on two 1060 to 50% and then use the same cable for those two GPUs, it's still unstable, even though it should only be using 100% of a normal 1060's power usage.
Other details: I have an Asus Prime Z270-A, with updated BIOS and the most recent Nvidia and AMD drivers.
Any idea how to fix the problem? Thanks!