That's what we get for buying something at launch. I can't even play my **bleep** games because AMD can't properly support a $600 dollar product at launch. Honestly bleep AMD, I might as well return this piece of **bleep**.
1. do a CMOS reset
2. update your bios
3. load optimized defaults
4. set PCIe to PCIe 3.0 (instead of AUTO or PCIe 4.0)
is your windows now on 20H2?
I am getting similar issue in VR but with a 6800 XT. GPU usage is fairly low generally < 50% (only in VR get full usage in 2d games) and oscillates up and down a lot, drops down to 0% many times, even though its not always running at 90 FPS in the head set so it has lots of reserve in there. My CPU usage per core is around 60 to 70% max so it doesn't seem to be a CPU bottleneck (running a 2700x). This is causing the stutters and framerate dropout for me and might be the same your getting.
I have put the min clock speed to around 2000Mhz, it just runs at around 800mhz and spiking up and down otherwise, but the driver doesn't seem to be seeing the headset as a demand and only what is being displayed on the monitor. I think due to this the usage is low and what the monitor is doing is easy for it as the res it a lot lower then the HMD. ACC seems the run the best which is odd as its unreal and AMD don't normally run well on Unreal based games. I am running a WMR HP headset and reprojection doesn't work at all with the 6800xt even when its at 55fps (with 40% GPU usage).
This is all on a fresh fully up to date install of windows with fresh latest 20.12.2 drivers. As this issue wasn't seen on Polaris (ran for 3 months as a stop gap to the 6800 xt) or Vega this must be a RDNA2 driver issue. Looking around forums it seems to be similar on RDNA 1 and hasn't been fixed so looks like VR isn't any priority for AMD which is a shame. I do a lot of sim racing in VR and bought the 6800xt mainly for VR so quite a disappointment, especially for the price, to find its not performing much better then my Vega64. I have submitted bug reports but not heard anything from AMD yet. If more people are able to submit this as a problem hopefully AMD might look into it and give us the VR these cards are capable of.
I did a clean Win 10 install because I got my new s.2 SSD. It seems that the games work a little bit better but still occasionally I get these high GPU frametime spikes. For sure tho, the GPU utilization is not varying like crazy from 0% to 100% anymore. Perhaps there was something left of old Nvidia drivers..
I have to do more testing. I think high GPU temperature could be one thing. My reference rx6800 xt goes up to 80 degrees in celsius while VR gaming.
yap - i recommend a "fresh install" when you had Nvidias driver installed - they do so much stuff to the system
about your temps - buy a good thermalpaste (or if possible liquid metal) and repaste your GPU
ps i am that old i prefer a cold card over a quiet card (as for competetive i use an headset anyway) = ramp up your fancurve ;)
I managed to get reprojection working properly in the end. Due to a clean install of Windows for some reason SteamVR switched it to permanently off. Turned it on in the settings when in the headset (can't see settings anymore on my monitor) and it seems to be working properly. I got reprojection triggering last night and was smooth when it was triggered.
I still have low GPU usage in VR and locked 120fps in 2d games (can't get it to go higher even with vsync off and FRC off) but with reprojection working it's not as noticeable. Still the GPU has alot more to give if AMD can fix the driver issues. What's odd is I have a frame time of 7ms but the FPS is at 70fps and I can see the spikes which cause the 70fps and not higher even though the frame time is 7ms (due to the spikes being so fast).
Hopefully a new driver will be released soon with bug fixes.
For me with Valve Index and SteamVR I can enable and disable "Motion smoothing". I suppose this influences the reprojection? But it did not have any noticeable effect on the stuttering. The reprojection value is usually 1-4 % but when big lag spikes appeared then it would go as high as 30%.
Since the video still has not uploaded, you can see it here (jaboust - Twitch).
I'm in the same boat. Just came home with a 6900XT. I did safe mode DDU clean, coming from an RTX 2080 Ti. Getting the same kinds of microstutters OP is experiencing when running any SteamVR game on my Valve Index. Every 30 seconds to a minute maybe on average all the frames just drop for about half a second. Then everything goes back to running buttery smooth. Definitely caused by the new GPU, I had no issues like this with my old one and nothing else has changed.
6800xt here, same issue as op and most other comments.
Have a 5900x cpu and before the 6800xt i had a 980ti in. Did a clean install of Windows, updated everything. All drivers installed.
Went from 9 cpu framtime to 16 and gpu utilization is all over the place and I get microstutters. This is in raceroom and Im using the exact same settings as I did with my 980ti.
I cant for the world understand why my cpu framtime increased so much.
I have tried every possible combination of settings in the game, in steamvr and in bios.
Going back to the stable driver I get a slideshow. So optional "works best" as I only get constant stutter.
Valve index is the HMD im using