WMR pegging C: disk performance at 100%

[Gray8]

I'm always struggling to get SteamVR performance somewhere acceptable with Windows Mixed Reality, and I've yet to manage it completely. I noticed something I hadn't before, and I was wondering if this happens for anyone else, or if Jonathan or anyone else from the Microsoft dev team could comment on whether this is expected behavior or if I have something wrong with my install somehow.

When running anything in SteamVR, it polls the C: drive (a super-fast NVME drive) at 100% for long chunks of time when I am moving my head in the headset. It appears to be accessing data in the following location:

C:\ProgramData\WindowsHolographicDevices\SpatialStore\HoloLensSensors\{00000000-4321-0000-0000-000000000000}

...where I am assuming the room data that is used to handle location awareness is stored. The actual edb database in there is only ~87MB, and the entire folder including log files is only 103MB. All of this would fit in ram easily, and the NVME drive could read or write that in far less than one second, which makes me wonder why there are many long stretches of 100% disk utilization to the folder... is some development/diagnostic process still going on that's aggressively polling the disk due to some phantom setting that didn't get switched off when I got the latest updates once the SteamVR integration went out of closed beta...?

Please see below for pictures illustrating the problem:

imgur album[imgur.com]

(the screenshots were all taken long after the games finished loading its own data from the disk and stabilized)

Since that is the only performance metric that seems to be hitting full utilization, I feel like this may be the source of all my WMR+Steam performance problems. Does anyone else see this behavior? You can test it by opening task manager and looking at the the C: graph under Performance while rotating the headset around in your other hand (while in a SteamVR game). You'll see periods where the disk is idle followed by long periods where it's 100% pegged. As you can see from the Resource Monitor picture, it is indeed Windows Mixed Reality that is doing this (WUDFHost, and you can see the file handles via resource monitor pointing to the holographicdevices folder).

Jonathan/Microsoft - is this expected behavior? Do I have a problem? Even if there's not a clear fix, if I could just get a confirmation that this shouldn't be happening I could put in the work to get a new test system loaded up, if it comes down to that.

Everyone else - is anyone else having this happen?

[bkrafty1276]

noticed similar behavior from my HP headset

[pixelcowboy79]

My performance is atrocious too, and it's seemingly random. Same here, GPU and CPU are nowhere near full utilization.

[B0bFunkHouse]

Same deal with the C drive, a few random 100% hits but moving the headset causes a constant stream of 100%. I wonder what MS will say.

[pixelcowboy79]

I only see an ocassional C: spike, nothing that looks too serious.

[Asphodel]

Same problem, causes a slow drop in performance while playing. Games start out smooth but after half an hour or so they get to the point of being unbearable.I am just assuming this is the cause of the performance drop simply because no other hardware in my pc is really getting worked too hard...

Edit:
I am using an SSD as C: and my games are in a separate WD Black 1TB

[Tsvetomir]

I had the same problem when I had HDD, it made me buy SSD, I reinstalled my windows 10 to the SSD and from that moment, I no longer have the problem.

[Ðadpòól]

Looked at your screenshot. I also use Windows Defender and do not experience this problem. I have SteamVR installed on C:\ (NVME SSD) and all my games on a separate SSD. Check your Windows Defender settings to see if you might need to add exceptions.

[Ðadpòól]

Also, perhaps check your Windows page file settings and try moving it to another drive.

[Asphodel]

With the page file settings, try setting the minimum to your ram x1024 to convert to mb, then set the max size to double that.

[Tsvetomir]

Reporting back, that now even with SSD its taking up to 50% and up to 20% CPU.

[alt]

I got a probably similar problem with my Lenovo Explorer. Event log shows abnormal waiting time when polling to same address you mentioned.

However in my case I got 100% disk active time once the device is plugged in (within the "look around" screen), and soon the OS level IO tasks on that disk start to fail (it is my OS drive as well). In the end Windows just ends up BSOD with kernel crash.

I suspect is it because the M2 SATA drive (mine) is not as good as a NVME drive in handling the heat, and just stops to work. Or the high active time queued the system tasks to trigger a BSOD.

I did try a brand new installation on a regular mechanical HDD, and the HMD works alright. So I doubt this has something to do with the Windows SSD strategy.

I will try your method of moving this file around and creating symbolic links. I will report back if that goes well.

[The Incredible Ryan]

If the room data could be custom installed, we could at least try to create a small ram disk to prevent this problem. I didn't test myself, but if it's true, maybe you should report how much ram your system has. Do you have 8/16/32Gb of ram ?

[rhylos]

Also noted extremely high disk utilization to the DB? files located at:

C:\ProgramData\WindowsHolographicDevices\SpatialStore\HoloLensSensors

Request if others have enough RAM to set up a persistent RAM drive to test performance using a hard symbolic link from the above location to their RAM drive and report if my much increased performance is a placebo effect.

I have 32 GB of RAM
OS on SSD
Games on 7200 RPM Drives
Symbolic Link to RAM Drive with Persistence and load from SSD on Boot
Nvidia 1070 SLI

Noted Archangle tends to spike the drive more that some of my other games. Elite Dangerous seemed to load faster.

[Captain Hook]

I also experince it.. really annoying and ssd killer

[Sgt. Nick Fury]

I haven't been technical enough to narrow down cause, but I can confirm the degradation of performance over time. I nearly always have to reboot after awhile to keep performance, and this includes running MS store stuff from cliffhouse, so nothing to do with SteamVR.