Originally Posted by zander
The problem appears to be a duplicate entry in the DSDT for the PCI-E bridge upstream of the discrete GPU. On the systems I looked at, the devices PEGP and PEG3 both refer to the bridge @ 00:03.0, i.e. both have an _ADR identifier with the value 0x30000. This indirectly causes the NVIDIA driver's ACPI handle lookup attempt to fail for the GPU in question, which in turns prevents the driver from obtaining important information via ACPI methods associated with the GPU.
How does the nvidia windows driver deal with this situation? Does windows merge the
two leaves with identical _ADR values?