drastic fps drop when switch to vr


I have a big scene with 7.000 actors in between 9 streamed levels, never more than 4000 at the same time in the visible levels. usually 2000 or less. When I play in screen my fps is really good, GPU takes 8 -11 ms to render

But when I switch tp VR it goes up to 60-120ms (8 times more) keeping the render resolution in 100% in Steam VR. There is a scene update process that passes from a 0.7ms to 40-80 ms

I have tried a few changes, first I try to switch off the stereo render and the time was similar, but now instead of taking all that time with the scene update, it shares that time with the visibility commands.

Try to reduce the visibility commands time by turning off the dynamic occlusion but it was slightly slower taking a little bit longer the base pass than the time saved.

checking the RSI the primitive calls are doubled or more when I switch to VR,

Round robin Occlusion is on, but also haven’t found big diference switching it on/off

I guess something I going the wrong somewhere, while I keep searching for a solution I will try using precomputed visibility in one copy of the project and using different level splits for more efficient streaming.

Thanks for any help on this