We are currently having same issue on our VR project. Unreal 4.11 preview 8. We have wmv video textures in our scene and up until now have been getting consistent 90fps and no problem with video playback. Since update 4.11 preview 8 however we get an exact half frame rate of 45fps and our cpu draw call jumps from 11ms to 22ms. Our plan now is to downgrade to 4.11 preview 7 but just want to make sure this doesnt continue into 4.11 official release.