Tried yesterday Standalone version with “t.maxfps 90” and “stereo on” for Vive VR, UE4 editor closed. The Framerate was steady 90 and constant deltaseconds between frames, graphicscard was scaling up from 40% to 80% load, all 8 CPU cores at about 50% load.
However when getting close to many objects at once, the framerate in the Vive is horribly, though 90FPS and const deltaseconds.
Performance when Editor is running is still bad, hardware not scaling up.
As well having problems with UE4 and Displayport (4k Monitor). The performance within viewport is great, but as soon as the viewport looses its focus (mouse out of viewport) the performance is horrible, about 1 second lag, even when hovering over something, the highlighting lags.
Tried downscaling to full HD and setting the resolution to full HD, does not change anything.
Out of UE4 the system runs well on displayport.
Using an adapter Displayport->HDMI and a HDMI->HDMI cable to connect the monitor, the performance is ok in UE4.