Glide

I have TrackIR, and I could create a stutter on demand by turning my head past the sun. I am guessing that if the shader cache hiccups then the handoff between VR/TrackIR and DCS gets interrupted.

Could be, it's very new. I can't test it with my card. My heart was literally pounding in my chest waiting for a stutter to happen for the first couple of days.

I know, it's amazing dogfighting now! Glad things are working. I turned up all my quality settings with Ultra Low Latency. BTW, if you have Reflex (my 1080ti doesn't), that's better than Ultra Low Latency according to that article.

BTW, Nvidia recommends Fullscreen mode in DCS. (See that article.) There's some confusion here because you can disable fullscreen optimizations in the Properties dialog for DCS.exe because apparently Windows adds compositing latency with it's full screen optimizations. I suppose the "out of the box" setup would be leave fullscreen optimizations ON and Fullscreen ON in DCS. I can't tell if there's a difference.

I've been testing out Low Latency Mode = Ultra with Vsync OFF. Nvidia recommends it. Seems to work fine. BTW, your 2080 should have Reflex mode which is better than Ultra Low Latency, according to that article. https://www.nvidia.com/en-us/geforce/guides/system-latency-optimization-guide/

Nividia recommends Low Latency Mode = Ultra with Vsync = OFF. Git that a try. Seems to smooth my FPS out. https://www.nvidia.com/en-us/geforce/guides/system-latency-optimization-guide/

I've been testing Low Latency Mode = Ultra. Nvidia recommends this set to Ultra with Vsync OFF. Works fine so far. BTW, Shader Cache = OFF moves the shader cache from disk to memory. You will notice a long load at "Wait Pooled Task -1" the first time you load a mission. These are the shaders being compiled. After that it will be fast to load if you get blown up and click "Fly again". https://www.nvidia.com/en-us/geforce/guides/system-latency-optimization-guide/

You can turn off Full Screen in DCS. Turn off Antialiasing Gamma Correction since you aren't doing AA in DCS. I leave Low Latency OFF, and Vsync OFF. Haven't tested low latency mode. Article on Low Latency Mode here: https://www.nvidia.com/en-us/geforce/guides/system-latency-optimization-guide/ Shader Cache OFF <-- MOST IMPORTANT. Trilinear Optimization OFF or ON and turn Anisotropic Filtering to X8. Don't really need it for the Low textures, but the other way should make things look nicer and not eat up too many frames per second. Otherwise, try dropping the resolution down one notch. You can enable FXAA in the NCP for cheap AA that doesn't drag down DCS. Try that if everything else works.

This might be a question for ED: if the Sun and Moon are both up, are they fighting each other over the shader cache? Can you "turn off" the moon for testing? I always try to have the moon around in my missions because it adds a nice cinematic touch. Good way to test: take a (multiplayer) mission that lags, move it to a day that has no moon, and compare.

Oh yes, shadows. Flat shadows just stick to things. They don't move around and call for things to be reshaded all the time. Your jet will cast shadows around, but the things on the terrain and inside the cockpit will stay in place. These things get reshaded as you change your angle to the sun or moon (the only two light sources in the game, i believe, I don't think muzzle flashes cast light. This would require clustered shading or Vulcan?). Flat shadows and no terrain shadows are the least stressful on the shader cache.

Those sudden stutters, reduce your visibility range down to High, and reduce the preload radius to at least 3/5ths of the range. The visibility range is like a bubble that surrounds the player as they fly, but only the part that's in the viewport gets rendered. When you swing your head around, all those textures coming across the boundary need shading. The larger the visibility range, the more pixels are crossing over the bubble boundary that will need shading too. Let me know how it goes!

Just some comments to help tune it up. FXAA is post-processing. This means that it's applied AFTER DCS is done rendering. You need to use Alt+Printscrn to capture FXAA. Since you are (correctly) not adding any AA load to the shader cache in your DCS settings, it does not add anything to have AA Gamma Correction on in the NCP. Since you have high textures, you might as well have Anisotripic 16x and Trilinear Optimization on (as you do). These help make great textures look even better. High textures put a higher load on the Shader Cache, I find Medium Textures are a nice compromise because Low Textures make the cockpits ugly, but with Medium textures I turn Anisotropic Filtering down to 8x and turn TriLinear Optimization OFF because why waste the energy on lower textures. Turn off Trees, Grass and Clutter. These things have a lot of geometry and require a lot of shading making the Shader Cache work hard. I know the WWII folks may not like this setting. Texture Filtering -Negative LOD bias should be Allow. Finally, try turning off all Vsync/Gsync settings and let your card go as fast as it can. This would mean adjusting the Low Latency Mode in your NCP. I find with FXAA and Shader Cache OFF, you don't need Vsync to make it smooth. I haven't seen a stutter in weeks. Cheers, and happy flying.

Nice work! See my discussion of shader cache here:

No mods of any kind. dcs.log

And, if you want the turbo experience, turn off all shadows. Not so visually appealing, but FXAA with shadows off and textures low is as fast as you can theoretically go at any resolution.

SSAA x2 gives much better framerates than MSAA x4 with HIGH textures at 4k. Set DCS SSAA to x2, MSAA to OFF, and NCP AA-Transparancy to Supersample x2). Framerates were almost good enough for VR IMHO.

If these theories are correct, turning down textures and resolution should take the heat off the shader cache. By the way, I can get stutter free performance with 4x MSAA, AA-Gamma ON, AA-Transparance = Multisample, MFAA ON, and all textures High at 4k. It just brings my FPS down to below 60 a lot. Still fine with me, but not enough for VR.

@BIGNEWY Looks related to time of day. I moved the clock and now I have shadows at takeoff. Seems that if you look at the sidewinder it gets a shadow, but if you look away, the shadow disappears. Sidewinder Shadow Test 3.trk

I can reproduce this, but it seems to happen at the end of a mission. I had no aircraft shadows at takeoff, but at landing I had shadows (but no sidewinders left to create shadows). However, my aircraft shadows did some funky dancing as I rolled down the runway at Al Minhad at the end of the mission.

Double click the box, press the key or key combination you want to bind, it should show up or you are under the wrong column. Close that dialog, double click the box again, press the new key to bind, and close the box. You should have two bindings now.

Thanks, @BIGNEWY This is one for Area-51. I have had terrain shadows turned off for weeks, and I have been wondering why my aircraft shadows were above ground sometimes, or below ground, or flashing on and off as I taxi along. I also had track file recording disabled in my autoexec.cfg, but I turned it back on for this test. I flew this one (attached) and saved the track, but you got a completely different mission. Now, when I fly it, my shadows are gone, as per my settings. I watched the track before attaching it this time. Cannot reproduce. Aim-9 Shadow Test 2.trk

@BIGNEWY Attached. Aim-9 Shadow Test.trk

I know this is a WIP. The shadows of the sidewinders and pylons are behaving strangely.

Some math to explain why this works. Assuming the DCS pipeline is working as designed, you can think of the shader cache as a set of gears. They will run the exact same way each time unless you change something. As soon as you add AA to the textures, you spin the gears of the shader cache. When it's on an HDD, it's awful, but on a SSD not so bad, and in memory (shader cache off) smoother but still stuttering (stripping gears). This is a multiplication problem. Add more AA and you get, not 10% more spin, but 2x and 4x more spin. Basically, AA makes the pipeline see more complex pixels and make more shader calls. Now look at the pixel counts and compare the amount of pixels we are pushing through the pipeline each second. This is why FXAA is the best strategy (until ED rolls out their planned upgrades); it let's the shader gears do the least amount of spinning at these high resolutions. Now I am turning off the FPS counter because that way lies happiness.