according to this slide from Oculus Connect 3 it should be possible to enable Asynchronous Space Warp (ASW) on Runtime 1.8, using a registry key:
I created a new DWORD-32 value ("1") as there was no further info about that. I had to create the whole structure as there wasn't any "Oculus VR, LLC" key under HKLM (only under HKCU).
Then I restarted the Oculus Software from the "Beta"-Tab in the settings. When running any VR app and pressing Numpad1-4 there is still absolutely no effect.
I also tried to create a new key (= folder) with name "AswEnabled" giving it the default value of "1". Nothing.
check your appdata local oculus folder for service files with the latest date. search for ASW and it will tell you why its not working. Are you on windows 7 or do you have a Geforce 7xx series graphics card?