GearVR File Download Workflow Unity3D

Hello developers,

I'm in need of a elegant way to download additional moviefiles (>500mb) upfront.

At the moment I have a startscene to download the files via www. But if the download module does a md5check the performance decrease dramatically. Is there a way to do the download of the files in background without affecting vr performance or directly after downloading the apk?

Thanks and best regards!