High VR textures causing dropped frames - Solved by turning HAGS on!

[edmuss]

For a couple of weeks I've been dropping frames in VR but only when main textures are set to high, initially I thought it was due to lack of VRAM but I'm not so sure now.  I generally run with most settings high (including ground textures) except view distance and shadows on medium and have no issues as long as main textures are set to medium.  Frametimes are good  at 11-22ms, motion smoothing engaged at 30fps and everthing is smooth.

The only way I can run high main textures is if I set the entirety of the rest of the settings to full potato, as soon as I turn up anything (shadows from off to low for example) it then fills the fpsvr graph with pink lines and frametimes jump up to 40-50ms; the underlying green graph between the pink lines is still around the 16ms mark.  Max everything else out with medium main textures and it's all happy again. VRAM usage is normally between 7.5 and 7.7gb no matter what texture settings I use.

Anyone with a 3070 able to run high main textures with a G2@100%?  Up until a couple of weeks ago I could and it only made a miniscule difference to the frametimes which leads me to conclude that something is amiss.  If it's potentially a bug how do I go about recording/reporting it or how would be best to find the cause of the dropped frames?  Likely that a repair is going to help?

Running latest OB, openvrfsr@75% and kegtys/speed-of-heat clearwater+IC pass shader mod.

edit: Turning HAGS on in windows10 appears to have solved this issue without any further detriment.  Turning it back off again results in framegraphs full of purple spikes on subsequent flights without a restart of DCS.

Edited January 26, 2022 by edmuss
updated title

[speed-of-heat]

try running the simplex shaders see if you still get the same problem ?

[edmuss]

Yup, same issue with simplex installed instead of clearwater+IC.

edit: if it's simply a case of the texture size has increased and I have to run medium then so be it, but the high textures don't look any higher than they did a couple of weeks ago and I suspect that there would be more people having issues if that were the case. I've tried removing the undervolt from the gpu (to keep heat and fan speed down) and it's still the same.  Reset the nvidia control panel settings to default (except high performance) and still the same.

Edited January 4, 2022 by edmuss

[dutchili]

Similar experience here. Textures on medium makes a huge difference. 

Especially in multi-player, setting main textures to high will give me the 'drop to 10 fps' issue with the 3070 & Oculus Quest 2.

I also suspected the compiled textures to be the issue, but none of the mods help.

It seems that the cockpit is rendered regardless of the actual Field Of View, otherwise the FPS would be similar to the LOW setting when looking at a blue sky.

[edmuss]

I think I've come to realise that this is the vram memory leak bug. If I load a mission I can run textures on high all round and it's fine, if I reload the same mission it then drops all of the frames. Restart DCS and it loads up just fine.

Anything I can provide to the devs to try to help support this?

[jurinko]

I run high textures with 3070, 1.0/100% @G2. After the latest OB and power service OFF cheat, performance is very good. Sometimes after few SP missions, the next one is very choppy and only restart helps - this is probably the VRAM leak bug.

[edmuss]

I have started using the low bit depth A10C normal maps that @Taz1004 did and I suspect that has recovered a bunch of vram usage, but like clockwork if I start up a subsequent flight without restarting DCS I get a wall of purple in the frame graph.  Switching between high and medium textures doesn't seem to make a huge difference to the actual frametimes.

[TCKnight]

Same problem here. I have same config, 3600 , ddr4 32gb 3600, nmve for dcs e 3070 @ 8ghz ram e 2030 Vcore. I fly with reverb g2…ss 100% e pd 1.3. All settings high and msAa x2… I have good fps, anche good refresh rate. I can fly only one mission… but I’m a old falcon 4.0 pilot, and restart the sim after mission. Your gfx settings ? Ps I have 35/45 fps… but change for mission and theater.

[edmuss]

Graphics settings attached, in open sky on Syria I'll be sitting around 12-15ms (85-65 ish fps), down low over Beirut it'll jump from 18-22ms (55-45 fps).  A10C II easy instant action it sits between 13 and 18ms unless a CBU crater has gobbled up all the frames!

I run the G2 at 60Hz so the frametimes can go all the way up to 30ms before motion smoothing starts to drop out, I can't reliably hold below the 20ms threshold to run 90Hz and keep the clarity and visual detail that I like - why spend all the money on the headset and GPU and run it looking like a calculator

Note that I also turn MFAA on in the nvcp and it makes a significant improvement to the shimmer for no cost to frametimes, as you run MSAA, turn it on and you can probably drop your PD down to grab some more GPU headroom.  Im still toying with terrain shadows, I like them on but it costs another 1-2ms.

[Dodge]

+1 to noticing the issue, and have done for some time. My own process is to restart DCS after a server restart, changing servers or settings change. While cumbersome, it seems to resolve the issue most of the time. 

[edmuss]

@TCKnight, @jurinko & @dutchili please see below, could you try turning on HAGS and see if it makes any difference to the problem? I've not experienced any negatives from turning it on so far but more testing needed!

 

 

[dutchili]

Thanks for the suggestion @edmuss. I've tried that once but it didn't give any results.

 

A few days ago I switched to the Virtual Desktop app (from Oculus store) in combination with Steam VR and fholgers performance kit. The issue seems gone!

So i think it was the Oculus VR stack that choked. In earlier contact with ED support the root cause was not determined through the DCS logs and dxdiag, which now seems to add to the conclusion that it was Oculus, not DCS.

I took a while to find the optimal settings in Virtual Desktop, but i ended up with:

- VD: select the graphics card you have (rtx 3070 in my case)

- VD: set sharpening to 8% (higher = pixelated, lower = just a bit to blurry, but better than a high value)

- VD: refresh rate 72 fps

- Steam VR: resolution per eye: 2000x2000 (approximately)

- DCS: textures medium, terrain textures low, most other list items on low, no msaa or asiotropicalasomething, Pixel density 1.6

- fholger: radius 0.2, quality 0.5, super sampling method: nis

end result: 36 fps reported by DCS without drops. I find it 'no fun' below 30 and 'okay' above 35, so this is good enough of a balance between smooth flying and graphics.

With Oculus the terrain looks much worse with the same DCS settings (and fps ofter much lower). After fooling around with the VD settings i can replicate the Oculus quality by selection a 'less performing graphics card', which, according to VD, determine the rendering resolution.

 

So I definitely recommend buying VD for EUR 19,99 and intalling fholgers performance kit.

 

I issue i still have is that multiplayer performance varies from one day to the other. yesterday it was 36 fps constant, today between 22 and 36. I don't know why yet, but i suspect the streaming bitrate in VD which seems to be based on the currently available network bandwidth. I need test some more, but on 'the good day', the setting was lower, which is hopeful.

 

[jurinko]

On 1/25/2022 at 10:24 AM, edmuss said:

@TCKnight, @jurinko & @dutchili please see below, could you try turning on HAGS and see if it makes any difference to the problem? I've not experienced any negatives from turning it on so far but more testing needed!

It seems to me that after the latest open beta I haven't experienced the sudden fps drop, hags off. But overall performance with 2.7.10 is slightly worse.

[edmuss]

I've not updated to latest OB yet but so far with HAGS on it's still not dropping the frames.