Check out my thread here:
http://www.assettocorsa.net/forum/index.php?threads/vr-performance-in-oculus-vs-ovr-modes.47367/
Update: Something big has changed in the oculus update yesterday and the one the day before, OR mode now has much improved performance, matching OVR mode.
I will include a guide here, in case you do not have a verified account at assettocorsa.net
This will lower your gpu usage 20-40% in openvr mode with the rift.
Under render...
Gpu usage 20%-40% less using openvr mode with rift
http://www.assettocorsa.net/forum/index.php?threads/vr-performance-in-oculus-vs-ovr-modes.47367/
Update: Something big has changed in the oculus update yesterday and the one the day before, OR mode now has much improved performance, matching OVR mode.
I will include a guide here, in case you do not have a verified account at assettocorsa.net
This will lower your gpu usage 20-40% in openvr mode with the rift.
Under render...
Gpu usage 20%-40% less using openvr mode with rift