Here's what the PSVR External Processor actually does

During a PlayStation VR panel at GDC 2016 SCEA senior developer support engineer Chris Norden, explained what the External Processing Unit actually does. If you're unfamiliar with what that actually is, it's a little black box that comes with your PlayStation VR headset, and it needs to be plugged into your console in order for the headset to function.

Apparently the Processing Unit doesn't actually provide any extra GPU or CPU power to the console as previously assumed, and can therefore not be thought of as a PS4 expansion or upgrade.

According to Digital Foundry, it actually does the following:

- It carries out object-based 3D audio processing ("really good and important to VR").

- It displays the social screen - undistorting the VR output for display on TV. Quality is lost in this process, so it scales the image up and crops it so you don't see edges.

- "Separate mode" - a completely separate audio and video stream you can send over to TV, as opposed to the mirrored social screen. It's sent compressed to the PU and then uncompressed by the device and sent to the screen. We're told that this was "an innovation that came quite late" in the development of the system.

- It displays PS4's system software interface in cinematic mode, handling the display of traditional 2D content.