AMD 6900xt tuning and settings for VR in dcs. My optimal recipe.

[TED]

I have been back and forward testing both nvidia 3080 and amd 6900xt and trying to decide which to keep. I’ve done so many hours and learnt so much going through not just dcs settings but all the various components of the pc. There is a lot of info about settings for nvidia and dcs but very little for amd, so here are my findings. 
I had almost given up on the amd after getting the 3080 nicely tuned, however I had this itch that I must be missing something with the amd as I wasn’t getting the performance I had initially hoped for, so I installed it again and went to work. The first point I have to make is while some of the logic in tuning amd or nvidia is the same, some is very different. Long story short, I now have the amd performing better in vr with a g2 than the 3080, which was also excellent once everything was setup correctly. Some of these processes will be applicable to both amd or nvidia and are generic.

system -

motherboard - msi b550 carbon gaming WiFi. 

AMD 6900xt.

Ryzen 7 3800xt (8 cores) overclock to 4.3. Air cooled.

RAM 32 gb gskill 3600mhz cl14. 

vr - reverb g2

1. Optimise the CPU. No matter what system you run this will help reduce stutters, increase FPS and reduce frame times. The key thing is that dcs only utilizes 2 cores so you need to dedicate 2 cores (2 physical and 2 virtual) to solely dcs. I used process lasso and went into core affinity and looked at all the processes. Set dcs to only use cores 12-16 and everything else in my pc to only use 1-11. Job done. After further testing the most important areas seem to be separating steamvr, voice attack and Srs from dcs. When adjusting the core affinity be cautious and DO NOT REMOVE ANY SYSTEM processes from all cores. Ideally identify what are the greatest users of cpu and separate them. Typically in dcs this is steamvr, wmr and dcs.exe. You don’t need process lasso for this and task manager will also work. Open details, right click on the process and set affinity.  Keep steamvr, wmr, Srs, away especially from the dcs cores. I’ve overclock done my cpu to 4.3 and it’s perfectly stable with air cooling. This seems plenty for my needs in dcs .

2. Optimise RAM. Into bios, enable x-amp profile and make sure you are getting the right ram frequency. Without x-amp enabled your system my be limiting your ram by default to 2133.

3. AMD software settings. My aim is to get a smooth visual with as little stuttering as possible, preferably at 100% resolution in steam vr. With nvidia the best way to do this was use motion vector and motion smoothing. This limits the FPS to 45. ED even say the aim for a good vr experience is a steady 45fps with low frame times. I agree. With that in mind my aim is to just do that. I don’t want it jumping from 80 to 45 and back to 80 as that just induces stuttering. For whatever reason the amd doesn’t like motion vector much, and that initially threw me off. However as I realized later, it doesn’t need it. In the amd software just set maximum FPS to 45 in graphics tuning. Apart from that I have everything else disabled except anti-lag. 
I found undervolting in preset or default gives good stability. I have since done a custom profile where I adjusted the fan speeds to keep the temp below 75. The amd likes to be under 75 degrees c to operate best. I found the cooling was a little too late so I increased the fan speeds at lower temps. That’s about it. A 10 min job!
 

4. Steam vr. Nothing special here. Global resolution set to 100%, video setting per app to 100%. Motion smoothing off. Advanced super sampling off. 
 

5 WMR - again fairly straight forward. Motion vector disabled. Force dx11 on. Don’t use the hand controllers in game. Just the mouse. 
 

6. DCS settings . Again keep it simple. MSAA x 2. AF x 16. Shadows flat. Forest visibility 50% forest detail start very low and gradually increase. I think trees look bad anyway so have it really low. Grass and clutter also very low and see how it looks. Everything else - textures, visibility, etc high. Clouds standard. The main ones are all on the right of the dcs settings. So pay attention to those sliders. In my view, trees, grass, clutter etc, doesn’t add an awful lot but can save a ton by turning it right down. 
 

7. General pc health. Make sure drivers are up to date. Minimize the amount of other programs and processes running in the background. Through windows or task manager set priorities accordingly with dcs being highest, and everything else low or normal. Possibly steamvr to high. Minimize all other windows once u r in dcs. Especially wmr and svr windows. 
If you are coming off an nvidia gpu, make sure you have removed every last bit of nvidia software and programs on your pc. This took me a while and I ended up having to download some removal software to get rid of it all. Some of this nvidia stuff really is like a fart in a space suit!

8. USB ports. Yeah…this one took me a long time to work out. Dodgy power supply from the usb especially to the g2 will definitely cause a lot of stutters. After almost a year I realized the usb power supply to my g2 was not entirely linear, causing small spikes and drops and it increased over time. The cable was basically crap. If you are getting lots of spikes then look into this. Anything that disrupts the power to the headset will cause surges and drops. It can be the reverb cable or the USB ports themselves. First check is to try different ports. Ideally for the headset a usb 3 port if you don’t have a usb c port in your gpu. However I think most 6900 have a usb c in the gpu. 
 

9. cooling. Sounds obvious but also took me while to work out. Keeping those temps down will go a long way. I don’t have any liquid cooling but put a bit of planning into decent air cooling with decent amount of cooling fans around the chassis and 2 fans in the cpu. Rising temps will cause the system to throttle back and ultimately cause performance issues and stuttering. 
 

With all this done I am able to fly sp with basically zero stuttering. It looks amazing and is very smooth. In mp it is a little more server dependent but in general very good with very little stutter. Especially if I am in a server with a ping well below 100. Dcs performance does vary a bit between modules. Most if my testing was in a10c2, AV8B and ka50. The a10 is the most demanding and even with that I was getting very good performance. 
Finally fpsvr! A great tool for diagnostics, but I have found it to be not always completely reliable. In fact sometimes it is actually FPSvr  that causes the frametimes increases and fps drops. So i uses it cautiously for comparison , then run with it off. Almost always a better appearance of performance once it’s off. 
 

There is probably more fine tuning that can be done, but I will now likely sell my 3080 and be sticking with the 6900xt. I am extremely pleased with the results. I have read a lot of reports of people dismissing the 6900xt and to be honest I nearly did the same myself. The problem is that you can tune and run the amd and nvidia in the same way, however with a bit of work and learning it’s my belief now that the 6900 outperforms the 3080 in dcs, and that is not intended as a negative to the nvidia. I got fantastic results out of that too and really can’t complain or say much bad about it. I hope this quick guide helps those who like me, perhaps have an amd 6900xt and got a bit frustrated. The good news is that it can and will perform really well, it’s just that the knowledge about how to get it working optimally is not really out there yet as the vast majority are still using nvidias. Good luck to all and please try some of the above and perhaps keep experimenting. I’m sure even more is possible. 

Edited January 11, 2022 by TED

[Steel Jaw]

Thanks brother.

Forcing DCS onto distinct cores with PL causes DCS to crash for me.

In VR, is there any visual difference or advantage to running Ultimate clouds?

[TED]

8 hours ago, Steel Jaw said:

Thanks brother.

Forcing DCS onto distinct cores with PL causes DCS to crash for me.

In VR, is there any visual difference or advantage to running Ultimate clouds?

I think in vr the new "ultimate clouds" basically doesn't work. There is a bit of a difference though in vr and ultimate look a bit better. In sp I will go for ultimate. In mp to keep some headroom i leave it on standard. 

Sounds strange that your dcs crashes when u dedicate cores. What cpu do u use and which cores did you use? It is possible one is a bad core and therefore not enough for dcs to run? 

Edited January 11, 2022 by TED

[edmuss]

I made this mistake of only capturing a single core for DCS, proper shuttershow

Once I had put my two fastest cores and their virtual components (3&4, 9&10) it all ran as normal, I can't say that cpu times in a SP mission were lower but there may have been a bit more stability of the CPU frametime.

[TED]

21 minutes ago, edmuss said:

I made this mistake of only capturing a single core for DCS, proper shuttershow

Once I had put my two fastest cores and their virtual components (3&4, 9&10) it all ran as normal, I can't say that cpu times in a SP mission were lower but there may have been a bit more stability of the CPU frametime.

Just try to make sure as well that nothing else at all is running in these cores unless it’s absolutely necessary. 
in PL just need to go to all process and highlight everything except dcs and untick the cores dcs are set to run on. 

Edited January 11, 2022 by TED

[Topo]

Thanks Ted, but when i force DX11 on like you said

10 hours ago, TED said:

5 WMR - again fairly straight forward. Motion vector disabled. Force dx11 on. Don’t use the hand controllers in game. Just the mouse. 

the image is very blurry...

Now, i'm with a 6900 XT on an intel system, 60hz with motion reprojection disabled.

 

I will try your settings as soon as possible, thanks.

[TED]

5 minutes ago, Topo said:

Thanks Ted, but when i force DX11 on like you said

the image is very blurry...

Now, i'm with a 6900 XT on an intel system, 60hz with motion reprojection disabled.

 

I will try your settings as soon as possible, thanks.

I’m using 90hz and found the dx11 forced on had no effect on image with the amd. I did however find the same early in in my testing with other settings, so I’m not 100% sure what caused that. With the settings above however the image is good.

I do think, like anything else with tuning, it is a combination of lots of small factors that combine and add up to produce results. There is no single silver bullet that operates in isolation. Everything is working together. The sum is greater than its parts.

Edited January 11, 2022 by TED

[edmuss]

I force DX11 on 60hz and it's clear as you like.  In my experience, blurry/muddy visuals are generally linked to resolution being below 100%.

The way I consider it: -

At 100% it theoretically should be one physical pixel per rendered pixel.
At 50% it theoretically should be two physical pixels per rendered pixel.
Between 50% and 100% it has to fudge the difference between the two with upscaling/downscaling and I believe that this impacts on clarity.

Other things to consider with blurry textures is the texture filtering quality, that is anisotropic and whichever options are in the GPU control panel.  Also in my experience WMR in high performance mode looks terrible, fast but indistinct.

[TZeer]

Thank you for sharing your findings. Appreciated.

[TED]

I should add one more important point i just found out as I have been adjusting further. Be careful when setting core affinity. It would appear especially system processes need to be on all cores. 

[TZeer]

Maybe edit your original post, so all essential info is in there and not "hidden" in some reply at a later stage. 

[Roller25]

10 hours ago, Topo said:

Thanks Ted, but when i force DX11 on like you said

the image is very blurry...

Now, i'm with a 6900 XT on an intel system, 60hz with motion reprojection disabled.

 

I will try your settings as soon as possible, thanks.

I had the same problem. It was because of the visual settings in Windows WMR settings being on 'best performance'. 

[Topo]

25 minutes ago, Roller25 said:

had the same problem. It was because of the visual settings in Windows WMR settings being on 'best performance

Thanks! I Will try asap

[Dodge]

@TED

>>>
8. USB ports. Yeah…this one took me a long time to work out. Dodgy power supply from the usb especially to the g2 will definitely cause a lot of stutters. After almost a year I realized the usb power supply to my g2 was not entirely linear, causing small spikes and drops and it increased over time. The cable was basically crap. If you are getting lots of spikes then look into this. Anything that disrupts the power to the headset will cause surges and drops. It can be the reverb cable or the USB ports themselves. First check is to try different ports. Ideally for the headset a usb 3 port if you don’t have a usb c port in your gpu. However I think most 6900 have a usb c in the gpu. 
 >>>

If you haven't done so already and your HP Reverb G2 is still within warranty, contact HP (ask for the Workstation team who double-up or take calls on half of VR) for the revision 2 of the cable. This will help reduce the issue reported

Part Number: M52188-001
Part Description: SPS-CA ACTIVE 6M BLACK /W SWITCH

Photo of the two cables can be seen here  (This is larger and has a power switch)

[schmiefel]

On 1/11/2022 at 12:11 AM, TED said:

in the amd software just set maximum FPS to 45 in graphics tuning. Apart from that I have everything else disabled except anti-lag. 

As I couldn't find an option to set this per application, has this to be set in the global video / graphics settings in the AMD driver edvery time before starting DCS in VR or is there another place where I could set this especially for DCS?

And many thanks for sharing your findings and tips ... I am just deciding if its worth buying a Power Color 6900XTU Red Devil Ultimate (its actually sold by Germany based Mindfactory online shop for 1.499€) to just get a much better VR experience in DCS (and maybe in FS2020, too, if I can get rid of the continuing CTDs there) with my RiftS (and maybe something better in the near future, but I hesitate buying a HP G2 because I don't like WMR at all plus there seems to be still a lot of qualitity trouble with this VR headset and my prefered Valve Index is still very expensive and other much better solutions are much more expensive and need an over the top system).

[MorphoV]

1 hour ago, schmiefel said:

As I couldn't find an option to set this per application, has this to be set in the global video / graphics settings in the AMD driver edvery time before starting DCS in VR or is there another place where I could set this especially for DCS?

I believe it's done in the "Radeon Chill" setting... but once I do that, my GPU frametime jumps up to 30ms.

It's promising though. So far the only way for me to avoid stuttering is to set the G2 to 60Hz, but it creates a very unpleasing flickering, especially noticeable on the highlights. 

[Topo]

20 minutes ago, MorphoV said:

So far the only way for me to avoid stuttering is to set the G2 to 60Hz, but it creates a very unpleasing flickering, especially noticeable on the highlights.

At first, i had the same problem (flickering); after a short time I no longer perceived it.

[streakeagle]

I haven't done any of the core affinity stuff. For me, the big difference was realizing the 6900 XT hated motion smoothing. Once I disabled the motion smoothing, the performance and stability skyrocketed. I can generally maintain 45 fps, even in an F-14 on a Super Carrier with fairly quality settings including mirrors, shadows, and heat blur at MSAAx2, AFx16.

The G2 looked great before, it looks fantastic now. Clarity in the cockpit is outstanding.

Edited January 21, 2022 by streakeagle

[Svsmokey]

Motion smoothing or reprojection ?

1 hour ago, streakeagle said:

I haven't done any of the core affinity stuff. For me, the big difference was realizing the 6900 XT hated motion smoothing. Once I disabled the motion smoothing, the performance and stability skyrocketed. I can generally maintain 45 fps, even in an F-14 on a Super Carrier with fairly quality settings including mirrors, shadows, and heat blur at MSAAx2, AFx16.

The G2 looked great before, it looks fantastic now. Clarity in the cockpit is outstanding.

 

 

[streakeagle]

Whatever it is that makes 90 fps out of 45 fps (motion reprojection?). With that turned on, the frame rate is unsteady, there are artifacts (blurry spots), and generally lower performance. If I force it off, my frame rates can vary between 45 and 85 when left unrestricted while having fairly high quality settings. It isn't 4K desktop quality, but it is getting pretty close. I would kill for a 90 fps lock, but the best I can manage if 45 steady, and even then some situations briefly drop the fps below 45.

[johnbowzer]

@TED, I thought if we are using STEAMVR we set the WMR settings to use STEAMVR per-app, not disabled? Or do you use disabled in wmr and not use the per app settings in steamvr settings, just the settings for video?

[TED]

4 hours ago, johnbowzer said:

@TED, I thought if we are using STEAMVR we set the WMR settings to use STEAMVR per-app, not disabled? Or do you use disabled in wmr and not use the per app settings in steamvr settings, just the settings for video?

I’ve  actually modified things a bit and now using mv and motion smoothing as well. So far it works well. I’m constantly testing new things but it seems this definitely works now. I actually set mv to auto now, not steamvr per app setting. 

[MorphoV]

When I use motion smoothing, the image is warping and ghosting. Don't you guys have the same issue?

Also, Am I the only one having the frametime increase when activating the Radeon Chill like suggested here? 

[TED]

I get no warping or ghosting. Definitely I don’t use Radeon chill. U use either default or under vault.

early on I did get warping with mv but force dx11 sorted this I think. There are just so many variables it sometimes gets a bit hard to know exactly what affects what, but I’m trying to slowly break it down and simplify it. Right now it’s all working good. I have definitely found I need to take the resolution down a bit in Whatever reason mp performance seems has have got worse in the last few months. I just do this with pd and leave everything else in svr. For mp often I need around 0.8 now.

[DeltaMike]

Ted, you are the absolute boss.

You had me doing the Newegg shuffle every day looking for a 3080ti.  No joy so far (but I did get the chance to buy a 3060 for my son-in-law, so, it does happen).   Unless I win Monday morning, I'm slapping in the 6900XT Monday night.  Looking forward to comparing notes.  

I like your strategy of capping FPS at 45.  I've read articles suggesting it's not precisely FPS that keeps you from puking, it's latency.  Everything between the time you pull the trigger, and see the results in your headset.   Which is primarily a function of render time, assuming your USB ports are working    Speaking of which, I'm assuming AMD has fixed things at the motherboard level, no?  Have you been able to run PCIE 4? 

Agree with your thoughts re: the GPU-mounted USB-C port.  Which I've only seen it on reference models.  Agree completely with your thoughts on thermals.  Glad to see the "one click" undervolting method actually does something.  

It's been a couple of years since I messed around with VR settings in DCS.  Before the new clouds and tress, and right at the beginning of VR optimization.   From looking at published results since then, I get the feeling things are quite a bit less sequential, and quite a bit more parallel, making it difficult to sort out what's affecting what.   

Back then, it was clear that MSAA, along with total number of pixels, was all on the GPU.  With that in mind, the fact you're able to run native resolution with any MSAA at all is a testament to the 6900XT and all the blood sweat and tears that went in to your tuning efforts.  Standing ovation for that.  That's yuge. 

As for the other settings, where we are primarily trying to regulate the CPU work load,  I imagine there are tradeoffs.   My plan is to set vis range to medium, which I personally feel is realistic.  With the old trees, that allowed you to turn the settings down without the weird "pop-up" effect; unknown if that trick still works.  But I agree, for jet pilots, trees and grass is kind of a waste of CPU cycles.  For water, medium worked well enough for me back in the day.  I'll try all that and see if that gives us any wiggle room with clouds and shadows.  (While I agree flat object shadows are fine, I shudder to think how much money I've spent on those doggone cockpit shadows, so, I want em.)  

I'm also planning to do a study of spotting distance, to see how undersampling and anti-aliasing affects that in the G2.  My theory is, native resolution is gonna be as good as it gets, but we will see.  

Thanks again boss.  I may come whining sometime during the next week.