According to the ASUS specs:
A
2 x PCIe 3.0/2.0 x16 (x16 or dual x8)
1 x PCIe 3.0/2.0 x16 (max at x4 mode)
4 x PCIe 3.0/2.0 x1
AR
1 x PCIe 3.0/2.0 x16 (x16 or dual x8)
1 x PCIe 3.0/2.0 x16 (max at x4 mode)
4 x PCIe 3.0/2.0 x1
The pics of both look indentical (same number and type of pcie connectors)
Based on the above I would assume that one of the slots on the AR is an unconnected dummy. But I have read in various places including here that some people have ASUS PRIME Z270-AR running 7 gpus and even 8 utilizing the M.2.
Can someone out there who actually has the AR version confirm (or deny) that it works with 7 GPU's?
I have both of them. The different A and AR is Onboard connection:
Z270A: 1 HDMI, 1 Displayport, 1 DVI
Z270AR: just 1 HDMI
Both use the same bios and can run 8 GPUs perfectly.