CtrlAltStudio has released a new version of their Oculus Rift Viewer: SDK 0.6: 22.214.171.124397.
The announcement is here: CtrlAltStudio Viewer Updated to Oculus SDK 0.6: 126.96.36.199397.
You’ll find the viewer works in Direct and Extended Rift modes. There are lots more little details discussed in the announcement.
I find this interesting, quoting David Rowe:
I can achieve a pretty smooth 75 FPS experience on the Rift if the scene’s not too complex, though only if I have my main monitor set to 120Hz. If I set it to 60Hz I only get a somewhat juddery 65 FPS on the Rift. I haven’t looked into this yet and am keen to hear how other people get on. Note: You can use Ctrl+Shift+1 to display a statistics window in Riftlook.
At 75 FPS it would be close enough to 90 FPS to be usable for extended periods.