Win7 Guest - using devices/webcam - slows down tremendously

[H0wdy]

F21 64 host
Win7 64 guest
Bus 001 Device 004: ID 0c45:648d Microdia

I've given up, for now, on using web cameras/webcam, as it only gives me a black screen, so I try to use usb devices/webcam. When I do that, it works, but it slows down the guest so severely that it is unusable.

Any way to resolve this?

[loukingjr]

Did you install the guest additions in your Win7 guest and are 2D and 3D enabled for the guest?

[H0wdy]

Yes, still incredibly slow webcam. If I do passthrough, I only get black screen film webcam.