What does MotionBlurSkinning do?

I was following the last post from this dx11 optimization guide by Chosker
https://forums.unrealengine.com/legacy-tools-unreal-engine-3-udk/udk-programming-and-unrealscript/1527467-dx9-vs-dx11-renderer

And indeed find that disabling MotionBlurSkinning does help quite a bit to recuperate those lost frame rates.But what does that option do? Is it something important to have turned on or does it deactivate motion blur completely?

On a side note, turning off ambient occlusion seems to help too under dx11.

IIRC it’s the one that allows using per-bone motion blur on skeletal meshes based on their individual bone motions. otherwise you get motion blur at the full actor motion

You mean something like 1:43 (swing weapon) and 1:48 sec in this video?https://youtube.com/watch?v=zN7jmMqxhKE
So turning it off is not a problem and we still retain some of that motion blur for the entire skeletal mesh?
Cheers

yep that should be right