I am trying to use a webcam in a Win 7 Virtualbox VM. The VM runs perfectly fine but as soon as I turn on the webcam, CPU usage bumped from 13% to 250%

These are the software and hardware versions
- 13" MacBook Pro 2018 (2.7 GHz i7 16 GB RAM)
- OSX 10.14 (18A391)
- Virtual Box Version 5.2.20 r125813 (Qt5.6.3)
- Windows 7 SP1 (8 GB RAM, 2 vCPU)
Any ideas to how can I reduce CPU usage when connected to Webcam?
Thanks,
Vikas