HoloLens SoC power utilization over 100% averaged over 1 minute

Copper Contributor

I everyone, 

I measured the performance of my HoloLens application and these were the results:

  • FPS: 46
  • CPU: 9%
  • RAM: 86.5 MB (private working set) 135.2 MB (working set) 164.7 MB (commit size)
  • SoC power Utilization: 116% (1 min average))

The HoloLens was connected to a workstation over USB. I am curious how it can be that the SoC power utilization is over 100%. Microsoft also stated the following:

“If an application is not achieving close to 60 fps, power consumption can be misleadingly low. Therefore, ensure that the application achieves close to target frame rates before taking power measurements.“

So is it just a misleading measurement or is there a mechanism I don´t understand? Can the SoC power utilization over 100%? In the SoC diagram there is a (red) area above 100%.

Thanks for any clarification.

In this post in the MS techcommunity is also a screenshot were a SoC consumption of 104% is shown: Example SoC

1 Reply

@CKunz1983 I don't know the answer to this for certain, but I do have a guess! I want to say I've seen similar numbers relatively often, but I don't have a ton of data for it so I could just be misremembering :)

Anyhow, my guess is that this could be something related to overclocking! Many mobile chipsets are underclocked for better battery life and thermal performance. In situations where the system may need more performance, or the app indicates that it's entering a performance critical part of the application, it's possible the system may decide to exceed normal parameters. ( See the BOOST part of the OpenXR spec for the performance settings extension )

 

Either way, I'd say you should absolutely be investing some extra time into performance profiling if you're up this high! In your case with only 9% CPU, this is almost certainly going to be shader performance and graphic asset optimization. There's an entrypoint to our MR performance docs over here: https://docs.microsoft.com/en-us/windows/mixed-reality/develop/platform-capabilities-and-apis/unders...

I hope that's at least a little helpful :)