A lot of you have been wondering what exactly the PlayStation VR’s external processor does. Speculation among many has been that it gives the PS4 extra processing power to handle VR and that the system cannot do that on its own. According to PlayStation engineer Chris Norden, that couldn’t be further from the truth. First, what the PlayStation VR external processor does not do:

• Provides no extra GPU or CPU power.
• Not any form of PS4 expansion or upgrade.
• Not directly accessible by the developer in any way – code cannot be written to it.

Norden:

 The PS4 is perfectly capable of 120Hz all on its own 

That means that all the gameplay you’ll see in front of you as you strap on PS VR is done purely by PS4. That last bullet point is also very important. This means that the external processor has very specific things it was designed to do but nothing that devs can tap into and utilize. Think of it like the RAM allocation of the PS4. Not all of it can be used for gameplay as some is set aside for the PS4 UI and other functions like live streams. However, there are other things that the external processor does that do help out with the overall gameplay experience. Those details after the jump.

According to Norden, the PlayStation VR external processor:

• Carries out object-based 3D audio processing (“really good and important to VR”).
• 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.
• Displays PS4’s system software interface in cinematic mode, handling the display of traditional 2D content.

In short, all the wonder of PS VR is handled by PS4 but the external processor provides additional power to run things like UI, audio, and some expanded gameplay options that developers can take advantage of. That likely has to do with multiplayer games in which one person wears PS VR and the other players use PS4 controllers (as seen above). Frankly, even if it did provide extra processing power for PS4, all that matters is the end result. Short of a technical based breakdown of the product, VR in most conversations will boil down to the experience, not the hardware that made it happen.

Discuss:

Do you care what that PlayStation VR external processor actually does?

[Via EuroGamer]