Microsoft reveals chip behind HoloLens

We've known the broad specifications of the HoloLens for some time, but Microsoft has given us some more details about what the mysterious “holographic processing unit” is, and what's powering it.

Revealed at the Hot Chips conference in California by Microsoft devices group engineer Nick Baker, The Register reports that the “HPU” is a custom made 28nm coprocessor created by TSMC. It has 24 Tensilica digital signal processor cores, backed up by 65 million logic gates, 8MB of SDRAM and 1GB of DDR3 RAM. The whole thing draws less than 10 watts of power.

So what does the HPU part of the headset actually do? In short, all the sensing of the wearer's environment, from collecting sensor data to processing the body's movements. Each of the 24 cores has a different task to focus on, and currently Microsoft says that none of the chips have been pushed past 50 percent capacity, meaning it should have an element of future proofing in place. 

The Register reports that the HPU can perform around one trillion calculations per second. Because most of the heavy lifting is done by the HPU, the HoloLens' CPU and GPU is largely left free to concentrate on running Windows 10 and its apps, rather that churning through environmental data. That's vital, because unlike the HTC Vive and Oculus Rift, the HoloLens is a standalone device that doesn't need an external computer to run. Everything you need for it to work is strapped to your head.