I have determined that the stability issue with 7 GPU’s IS a problem with XFX cards, possibly with the MSI mobo or the Nitro Sapphire GPU’s. I have one 7 GPU rig that has been stable for quite some time and another that refuses to run stable with more than 6 GPU’s. The stable rig was all Nitro Sapphire RX480’s and the unstable rig had 4 XFX RX480 and 3 Nitro Sapphire’s. I moved one XFX card to the stable rig and it has now become unstable (even with the XFX card in a x16 slot). The weird part was it took a couple of weeks of running before it became very unstable. If I move that same XFX card to a Asrock mobo or put it in a 6 GPU rig it runs stable, so its not the GPU itself but an interaction with the other hardware.
So the brand mobo and GPU combinations are critical for 7 GPU stability. If I buy 3 more XFX cards I can test a rig with all same brand and type GPU and determine if it is the actual XFX cards, mixing in the Nitro Sapphire cards, or certain mobo’s like certain brands of GPU’s.
