Micro-Stuttering; Will increasing RAM speed make much of a difference for VR in this day & age?

[obious]

Given that we've had MT for a while now and most of the bugs people saw early on have been quasahed, I'm wondering if RAM speed still plays an important role in VR? 

I currenlty have 32GB of Corsiair Dominator RAM (CAS16, 3600Mhz) and given where RAM prices are at the moment, I wonder if it'll add much to my experience if I switch to a kit running at 4000Mhz (current limit of my mobo).

Overall, my Quest Pro VR experience with multi-threading has been positive but I suffer from what only can be described as micro-stuttering from flying even simple quick start missions (NTTR F-18 Free Flight mission for example) and am trying to think of what hardware changes I can make to improve things (GPU frametimes are siting about the 5ms that mission). I'm already running Tubo Mode from the OpenXR Toolkit which has definitly helped but the seemingly random micro pauses are detracting from the overall experience andw enjoyment. 

Thanks

[Steel Jaw]

My 64GB of RAM says no difference.  Look elsewhere, brother.

[obious]

5 minutes ago, Steel Jaw said:

My 64GB of RAM says no difference.  Look elsewhere, brother.

I’m not necessarily talking about increasing the amount of memory I have, just the speed 

[Steel Jaw]

3 minutes ago, obious said:

I’m not necessarily talking about increasing the amount of memory I have, just the speed 

Oh yes I see, then Id say "no".  Very small improvement in general performance, probably only see it in benchmarks, and its expensive,

[Burt]

I think I asked the same question a few years ago somewhere can’t remember but I do remember it was a no answer. But was told to use msaa x2 to lower micro stutters. 

[ShaunX]

15 hours ago, obious said:

Given that we've had MT for a while now and most of the bugs people saw early on have been quasahed, I'm wondering if RAM speed still plays an important role in VR? 

I currenlty have 32GB of Corsiair Dominator RAM (CAS16, 3600Mhz) and given where RAM prices are at the moment, I wonder if it'll add much to my experience if I switch to a kit running at 4000Mhz (current limit of my mobo).

Overall, my Quest Pro VR experience with multi-threading has been positive but I suffer from what only can be described as micro-stuttering from flying even simple quick start missions (NTTR F-18 Free Flight mission for example) and am trying to think of what hardware changes I can make to improve things (GPU frametimes are siting about the 5ms that mission). I'm already running Tubo Mode from the OpenXR Toolkit which has definitly helped but the seemingly random micro pauses are detracting from the overall experience andw enjoyment. 

Thanks

I had the same problem, random micro stutters even when frame rates were green and stable in both ST and MT.

On some advice I turned HAGS on for the first time. Micro stutters completely disapeared and everything generally more stable.

Worth a try though doesn't seem to work for everyone and may just be an AMD or WMR thing.

 

 

[Hiob]

Increasing the RAM-speed will not help with microstutters.

Those kind of issues are almost always caused by software interrupts/drivers/windows or application issues/settings.

15 hours ago, obious said:

I currenlty have 32GB of Corsiair Dominator RAM (CAS16, 3600Mhz) and given where RAM prices are at the moment, I wonder if it'll add much to my experience if I switch to a kit running at 4000Mhz (current limit of my mobo).

Waste of money if you ask me.

Unless I was to build a completely new system which would need a complete new kind of memory, I wouldn't throw my money out for a few MHz of RAM-Speed.

(Well, that's not true actually - I wasted money on less. But that was dumb af..... )

Edited August 15, 2023 by Hiob

[obious]

14 minutes ago, Hiob said:

Increasing the RAM-speed will not help with microstutters.

Those kind of issues are almost always caused by software interrupts/drivers/windows or application issues/settings.

Waste of money if you ask me.

Unless I was to build a completely new system which would need a complete new kind of memory, I wouldn't throw my money out for a few MHz of RAM-Speed.

(Well, that's not true actually - I wasted money on less. But that was dumb af..... )

 

Ha got it. Thanks 

[slughead]

I am not or rarely seeing micro stutters now. I take it by micro-stutter you mean a single skip of the landscape and not ASW/reprojection judder?

As you are using a QP, get the quad view foveating rendering enhancement from here. This will give you 58% fewer pixels for your GPU to push and you will barely notice a difference. What you will notice is a large gain in headroom and the micro-stutters will mostly go away providing you haven't got some other process running on your right causing your problem.

Also, is your motherboard PCIe 4.0 or 3.0? If 3.0, you are not getting as much bandwidth to your GPU (4090) as you could and this could be a significant factor.

Your sig shows you running at 5.2GHz. That may be ok at idle but what is happening under load? If the thermals are high, the CPU is likely to be thermal or power throttled and you could end up running much much slower than if you didn't overclock it.

I am running a 13900k at stock settings, i.e. not manually overclocked.

Also, also... are you running Win10 or 11? Win11 I believe is better for new intel processors and is designed for them whereas Win10 isn't.

[obious]

1 hour ago, slughead said:

I am not or rarely seeing micro stutters now. I take it by micro-stutter you mean a single skip of the landscape and not ASW/reprojection judder?

As you are using a QP, get the quad view foveating rendering enhancement from here. This will give you 58% fewer pixels for your GPU to push and you will barely notice a difference. What you will notice is a large gain in headroom and the micro-stutters will mostly go away providing you haven't got some other process running on your right causing your problem.

Also, is your motherboard PCIe 4.0 or 3.0? If 3.0, you are not getting as much bandwidth to your GPU (4090) as you could and this could be a significant factor.

Your sig shows you running at 5.2GHz. That may be ok at idle but what is happening under load? If the thermals are high, the CPU is likely to be thermal or power throttled and you could end up running much much slower than if you didn't overclock it.

I am running a 13900k at stock settings, i.e. not manually overclocked.

Also, also... are you running Win10 or 11? Win11 I believe is better for new intel processors and is designed for them whereas Win10 isn't.

I’m running at 90fps with a PCIe 5 (Z690 TUF WifI) motherboard. I’m also running a water cooled setup and thermals have never been an issue. As well as my overclock, I’ve disabled e cores so I’m forcing DCS to run on the performance cores and I’ve also disabled hyper-threading. I am however running Windows 10 which could possibly be an issue?

I did experiment with the DFR mod but tbh, it feels like a bit of a ‘hack’ given all the steps you have to go through so I turned it off (I also was seeing a very noticeable ‘box’ in the centre of my FOV which I can only deduce as being caused by the border where the DFR shifts from high-res sections of the quad view to low-res. It wasn’t immersion breaking but was a little annoying to say the least). 

Are you running turbo mode with OXRTK? Like I mentioned above, my experience with micro-stutters goes away when I enable turbo mode which is a bit annoying as I loose the ability to see how hard (or not) my system is working. 

I may test out a Win 11 install later tonight with a spare SSD I have lying around.

[slughead]

13 minutes ago, obious said:

water cooled setup and thermals have never been an issue

Me too but you could still reach a point where the processor thermal and/or power throttles itself. If you run the Intel XTU software you can see if this happens.

 

14 minutes ago, obious said:

I’ve disabled e cores so I’m forcing DCS to run on the performance cores and I’ve also disabled hyper-threading.

I haven't disabled e cores and I have hyperthreading enabled. I also have HAGS enabled and DCS MT set to high priority along with the Oculus Server set to high priority. 

 

15 minutes ago, obious said:

very noticeable ‘box’ in the centre of my FOV

That may have been the "bloom effect" setting under the VR options causing that. It needs to be off as per the instructions.

 

16 minutes ago, obious said:

Are you running turbo mode with OXRTK

I run turbo mode as part of QVETFR.

 

The other performance gain you can get is by reducing the FOV slightly to .85.

You also say you are running at 90Hz. I run at 72Hz. That's a bit performance boost again.

[obious]

31 minutes ago, slughead said:

Me too but you could still reach a point where the processor thermal and/or power throttles itself. If you run the Intel XTU software you can see if this happens.

 

I haven't disabled e cores and I have hyperthreading enabled. I also have HAGS enabled and DCS MT set to high priority along with the Oculus Server set to high priority. 

 

That may have been the "bloom effect" setting under the VR options causing that. It needs to be off as per the instructions.

 

I run turbo mode as part of QVETFR.

 

The other performance gain you can get is by reducing the FOV slightly to .85.

You also say you are running at 90Hz. I run at 72Hz. That's a bit performance boost again.

I don’t think my microstuttering has anything to do with the CPU and I can toggle turbo mode on and off in game and the stutters appears and disappear accordingly. I had bloom turned off as per the instructions for DVR and I did try running my QP at 72Hz but I got an intolerable flickering that I couldn’t handle. 

I don’t think FPS/frametimes are the issue as I have plenty of headroom (my testing missions is a simple free flight mission in the PG using the F18); my CPU frametimes are around 4ms with my GPU frametimes sitting around 6ms

Edited August 16, 2023 by obious

[slughead]

13 minutes ago, obious said:

I don’t think my microstuttering has anything to do with the CPU and I can toggle turbo mode on and off in game and the stutters appear and disappear accordingly. I had bloom turned off as per the instructions for DVR and I did try running my QP at 72Hz but I got an intolerable flickering that I couldn’t handle. 

I don’t think FPS/frametimes are the issue as I have plenty of headroom (my testing missions is a simple free flight mission in the PG using the F18); my CPU frametimes are around 4ms with my GPU frametimes sitting around 6ms

Perhaps. You've now got more information to go on now though which isn't hearsay. 

I am on 2 sx 32GB (64GB total) DDR5 DRAM at 5200MHz with a Gigabyte Z790 motherboard and an i9- 13900K processor.

[obious]

17 minutes ago, slughead said:

Perhaps. You've now got more information to go on now though which isn't hearsay. 

I am on 2 sx 32GB (64GB total) DDR5 DRAM at 5200MHz with a Gigabyte Z790 motherboard and an i9- 13900K processor.

Hmm, I’m thinking of building a new rig when the 14th gen Intel CPUs come out but it’s interesting that you’re not seeing any microstuttering with your rig which is significantly more powerful than mine. 

BTW, I take it you don’t have the same experience with toggling turbo mode on vs. off like I do (ie you have no stutters when doing barrel roles etc with turbo mode off?)

[slughead]

Microstutters with barrel rolls? The micro stutters I am talking about are flying straight and level, say 3000 ft AGL looking to 3 or 9 o'clock and towards the ground and used to see the landscape skip once maybe every few seconds. This is typically the app losing sync with the headset and skipping 1 frame.

Barrel rolls are huge changes of movement such as fast high G turns so this sounds to me that you are seeing fps drop below the refresh rate of the headset and switching to projection (if you have that enabled). If not enabled it would be a far worse experience. We normally call this judder rather than "micro" stutter.

If you are running at 90Hz, you will be hitting the limits of your system much more often and easier.

No CPU upgrade is going to help with this. Vulcan might with multi-threaded GPU API.

Perhaps if you could try to capture this using OBS studio and put a video on youtube we can be certain that we are on the same page. There is an OpenXR plugin for OBS studio so you can capture the VR stream rather than the mirror. I haven't tried it myself yet.

[Hiob]

This is general problem which makes identifying root causes so difficult: There is no objective definiton for "micro-stutters".

A skip every few seconds isn't what I would refer to as micro-stutters. Micro-stutters for me is when you have a continuous motion, but it isn't fluid and instead has like a micro sawtooth pattern to it (lack of better words).

Not talking right or wrong here! Just pointing out that it is hard to discuss a topic that has a different shape in everyones head. (Same applies to TrackIR-problems e.g.)

[WipeUout]

One thing you may try is to assign priority interrupt for your graphic card.  Run the attached file as administrator, locate your GPU in the list, click on the msi box to so it turns blue, click apply and re-boot your rig.  After boot, run again and check that there is a dash next to the irq number to ensure msi is activated.  In some cases this has improved micro-stuttering where there is competing priority between sub-system trying to get the CPU's attention.   

Msi Mode.exe

[dankmaster]

The problem is unoptimized code.

Even at hundreds of fps if vram is not managed properly you'll start swapping to disk and any system will then stutter.  When this is happening, task manager shows "GPU Copy" and your disk IO gets saturated.

[obious]

Just to clarify a bit more, the ‘micro stuttering’ as I refer to it as doesn’t just happen when I do fast barrel roles. It also happens if I do a flyby of an aircraft (whilst looking at it) or just look around the cockpit. I wouldn’t say it’s every few seconds on a repeatable basis either but certainly happens 2-3 times in a 10-15 period. 
Just to be clear again, this issue goes away with turbo mode enabled and comes back when it’s off (every single time). 

Edited August 16, 2023 by obious

[obious]

3 hours ago, WipeUout said:

One thing you may try is to assign priority interrupt for your graphic card.  Run the attached file as administrator, locate your GPU in the list, click on the msi box to so it turns blue, click apply and re-boot your rig.  After boot, run again and check that there is a dash next to the irq number to ensure msi is activated.  In some cases this has improved micro-stuttering where there is competing priority between sub-system trying to get the CPU's attention.   

Msi Mode.exe 35.5 kB · 1 download

Tried this, had no noticible impact. Thanks for the suggestion

3 hours ago, Hiob said:

This is general problem which makes identifying root causes so difficult: There is no objective definiton for "micro-stutters".

A skip every few seconds isn't what I would refer to as micro-stutters. Micro-stutters for me is when you have a continuous motion, but it isn't fluid and instead has like a micro sawtooth pattern to it (lack of better words).

Not talking right or wrong here! Just pointing out that it is hard to discuss a topic that has a different shape in everyones head. (Same applies to TrackIR-problems e.g.)

Thinking about it a bit more, this is actually a more acurate description of what I experience (micro 'sawtooth'/tears in the image)

Edited August 16, 2023 by obious

[Lange_666]

I'm having the same problem with MT when OpenXR Turbo isn't set to on.
If set to off, micro stutter, if set to on, smooth. (noticed same thing with Rift-S and Pico 4).
Setting it to on comes with a drawback of small black flickering bands on left and right side of the view when head is moved quickly.
Therefore i prefer ST for VR and only run MT in 2D mode.

For me it's an OpenXR problem because when running MT through Oculus api (yup, it's possible) OpenXR toolkit doesn't work and then there is no micro stutter on MT and no black side banding either. It then looks / behaves like ST does.

Edited August 16, 2023 by Lange_666

[slughead]

1 hour ago, obious said:

Just to clarify a bit more, the ‘micro stuttering’ as I refer to it as doesn’t just happen when I do fast barrel roles. It also happens if I do a flyby of an aircraft (whilst looking at it) or just look around the cockpit. I wouldn’t say it’s every few seconds on a repeatable basis either but certainly happens 2-3 times in a 10-15 period. 
Just to be clear again, this issue goes away with turbo mode enabled and comes back when it’s off (every single time). 

 

That's your system unable to keep up with a 90Hz refresh rate. As soon as that happens, you end up in projection. Aircraft flying past fast whilst in projection appear double or ghosted. This for me is not micro stutter. It's much more pronounced. With the landscape, people refer to it as a judder during high G turns. You'll either need to reduce the headset refresh rate, or turn down your settings. You' won't get rid of it completely though. The more demanding the terrain (cities, buildings, objects), multiplayer etc the harder it is to stay out of reprojection.

[obious]

2 hours ago, slughead said:

That's your system unable to keep up with a 90Hz refresh rate. As soon as that happens, you end up in projection. Aircraft flying past fast whilst in projection appear double or ghosted. This for me is not micro stutter. It's much more pronounced. With the landscape, people refer to it as a judder during high G turns. You'll either need to reduce the headset refresh rate, or turn down your settings. You' won't get rid of it completely though. The more demanding the terrain (cities, buildings, objects), multiplayer etc the harder it is to stay out of reprojection.

You know what, I’m starting to think this may be exactly what it is. I’m running 1.7x rendering resolution in the Oculus settings (slider is all the way to the right) and I’m maybe thinking I should turn it down as whenever the ‘micro stuttering’/whatever happens I notice my FPS dips to ~82-83fps before rising back up to 90. 
This is even more proven by the fact that I just spent the last two hours installing windows 11 on an empty NVME drive, I had lying around only to experience the exact same behaviour

Edited August 16, 2023 by obious

[slughead]

9 hours ago, obious said:

You know what, I’m starting to think this may be exactly what it is. I’m running 1.7x rendering resolution in the Oculus settings (slider is all the way to the right) and I’m maybe thinking I should turn it down as whenever the ‘micro stuttering’/whatever happens I notice my FPS dips to ~82-83fps before rising back up to 90. 
This is even more proven by the fact that I just spent the last two hours installing windows 11 on an empty NVME drive, I had lying around only to experience the exact same behaviour

 

Turn it down to 80 and try again. Of course, if it drops lower than 80 you will have the same ghosting of fast-moving planes. It's all a trade-off.

[obious]

FYI, I think this is defo an issue with the MT instance of DCS: