MT CPU Bottlenecking

[cyristvirus]

Hello,

 

I have an i7 8700k and with MT I am getting lower frames than before with all aircraft in same settings. FPS indicators say CPU bottlenecking with around 20% of the cpu being utilized. This also occurs in the menus.

I'm hearing similar reports from a few people in discord with similar processors.

 

System specs

i7 8700k, 3080, 64 gb ram

Edited March 11, 2023 by cyristvirus

[nighteyes2017]

yep, seeing exactly the same thing. 

got no improvement whatsoever in VR. MT seems to be slightly worse even.  

MT version with FPS indicators says cpu bottlenecking at 20-22 percent of useage.

 

[Toad McFrog]

Same behavior for me, but I'm running a Ryzen 5 so I don't think it's processor specific.  I saw a very small increase in VR (3 FPS or so).  Showing CPU bottlenecked at 25ish percent utilization. 

[Sparkam]

Similar. Most of the time I see flickering 'CPU bound (rendering thread)' in MT VR OpenXR i7 8700K, 1080TI, 32 GB

 

[cyristvirus]

I dont have the ability to troubleshoot right now due to traveling but is anyone using vr and using an external multiplier? If so you see if removing the external dpi multiplier helps?

7 minutes ago, Sparkam said:

Similar. Most of the time I see flickering 'CPU bound (rendering thread)' in MT VR OpenXR i7 8700K, 1080TI, 32 GB

 

Even in the menus I get cpu bound and 20% utilization like this.

[Andy1966]

Hi All, you may want to try doing a slow repair. I have seen quite a few people saying they had a drop in perf. and a slow repair fixed it. 

[cyristvirus]

28 minutes ago, Andy1966 said:

Hi All, you may want to try doing a slow repair. I have seen quite a few people saying they had a drop in perf. and a slow repair fixed it. 

Thanks for the suggestion. I did see that for some people this worked, but for others it did not.

[gorzasty]

Same problem here. I did slow repair and something was change but not sure was it in good direction  Before repair it was smoother experience in simple scenario (like free flight on Caucas in Mi-8) but there was a lot of spikes in frame time window (green line spikes to the bottom of the graph). After the repair there is nicer green line, but sometimes (every few seconds) there come large spike - sometimes to the top which causes really bad stutter during flight.  All the time I have CPU bound message, even in main menu.

 

Here is video: 

  

[dutchili]

Same here:

 

[Wali763]

I have the strange situation, that in ST (non-MT) in normal (lighter) missions my cpu-frametimes are lower than in MT. At the same time Fps-tracker in MT constantly says "CPU bound rendering thread", whereas in ST there is no message. 

I get the frametimes from Frame-Timing-Overlay in the OpenXRTools (not toolkit), but the fps-counter in DCS seems to support those numbers. It seems, that CPU-frametimes in MT try to stay around 10,5ms.

So, where in ST I get eg 8ms CPU-frametimes in MT I get 10-10,5ms. Thats actually in contrast to what MT should do, meaning lowering CPU-frametimes.

At the same time the GPU-frametimes drop a bit by ~1ms, which gives some more headroom for higher video-settings.

In larger missions MT is working to some degree. Its lowering the CPU-frametimes in situations where in ST I got 17ms CPU-frametime to 11-12ms in MT. But since (in my case im running my G2 without reprojection to get to full 90fps) this is too high for real 90fps, I get stutters. If those were arount 10ms or lower all would be good.

Even those 10,5ms are pretty close to the needed 11,1ms for 90fps, overhead in lighter missions is not that big so I get an almost smooth 90fps ride in lighter missions. But in heavier missions, this overhead might to get too big, so it causes fps to often drop below 90fps which gives visible stutter and spikes in the DCS-framecounter.  

 

Edited March 12, 2023 by Wali763

[Leafcutter1008]

Same here, CPU bound in VR although my rig is quite decent. I have sent my log files to support. I think the more people do this, the easier it will be for them to find and fix the problem.

[Special K]

Just some ideas:

- Make sure that HT/SMT is enabled (I see it is for you guys, but it should be checked, as we told a lot of people to disable it in the past as it was better back then).
- If you see a lock at 60, that sounds like there is VSYNC active somewhere.
- Make sure you deleted Saved Games\DCS(.openbeta)\fxo and metashaders2.
- If no joy, try deleteing %LOCALAPPDATA%\TEMP\DCS.openbeta (or DCS for you steam users).
- Check Saved Gamed\DCS(.openbeta)\Scripts\Exports.lua. I've seen winwing doubling and trippling their exports in there. If unsure, just rename the file to Exports.old and see if your issues vanish. Then we can work from there.
- Disable Windows Game Mode.
- In your Nvidia control panel:
   - Make sure that Threaded Optimization is turned on (not auto) for your DCS World profile. We've seen some suspects that auto is not fully working.
   - Enable the performance settings on the Power saving and Texture Quality values.
   - Set low latency mode to Ultra.

[MrShooty]

I'm getting 45-50 FPS in ST and dropping to a lower quality 18FPS in MT. Consistent across modules and maps.

CPU, GPU and RAM are 22, 63, 45% utilisation in MT and 13, 98, 50% in ST. I'm feeling that CPU should be much higher if MT was working - but I'm a novice so advaice would help.

I have a i9 12900k, 64Gb RAM, 3080Ti and use a Reverb G2.

I've fiddled around with the NVida control panel as recommneded by SpecialK above, cleared the fxo and shaders2 files in saved games, run a cleanup and (fast) repair. I'm about to do a slow repair. But at each stage when I've checked th e FPS in MT remains absolutely rock solid at 18-19 FPS - surprisingly consistent.

Any suggestions will be much appreciated.

 

[Glide]

2 hours ago, Special K said:

Make sure that HT/SMT is enabled

HT is not required for MT.  I have mine disabled, and it's fine.  Disabling it fixed the missing labels for me. 

[amigastar]

I have a question,

what Graphics API does the new MT use?

I'm still having DX11 while using MT. I thought it will use Vulkan?

Is DX11 correct?

[diego999]

1 hour ago, amigastar said:

I have a question,

what Graphics API does the new MT use?

I'm still having DX11 while using MT. I thought it will use Vulkan?

Is DX11 correct?

Vulkan is not here yet. It will come (hopefully) at some point this year.

[amigastar]

So DX11 is correct?

Waiting for Vulkan.

[Special K]

Am 13.3.2023 um 18:14 schrieb Glide:

HT is not required for MT.  I have mine disabled, and it's fine.  Disabling it fixed the missing labels for me. 

It is not required, but as DCS can use up to 16 threads, why limit the possibilities. As this thread is about CPU bottlenecking, I would use all possible ways to counter that. One is enabling HT.

Which missing labels are you talking about?

Am 13.3.2023 um 22:25 schrieb amigastar:

So DX11 is correct?

Waiting for Vulkan.

Yes, DCS still uses DirectX11. It was not the plan to change the graphics API with MT. This is planned for a later change.

[Rainer_B.]

Tooltips are missing

[Glide]

1 hour ago, Special K said:

Which missing labels are you talking about?

The issue where labels only appear in one eye.  As for HT, it is a know fact that timeslicing adds latency.  That's why process lasso improves performance.

[Special K]

vor 12 Stunden schrieb Glide:

The issue where labels only appear in one eye.  As for HT, it is a know fact that timeslicing adds latency.  That's why process lasso improves performance.

Ok, you're talking about a VR issue. That might be, not a VR guy. For 2D, all I can say is that HT enabled gave me 20% more FPS than disabled.

[mac22]

On 3/13/2023 at 3:00 PM, Special K said:

Just some ideas:

- Make sure that HT/SMT is enabled (I see it is for you guys, but it should be checked, as we told a lot of people to disable it in the past as it was better back then).
- If you see a lock at 60, that sounds like there is VSYNC active somewhere.
- Make sure you deleted Saved Games\DCS(.openbeta)\fxo and metashaders2.
- If no joy, try deleteing %LOCALAPPDATA%\TEMP\DCS.openbeta (or DCS for you steam users).
- Check Saved Gamed\DCS(.openbeta)\Scripts\Exports.lua. I've seen winwing doubling and trippling their exports in there. If unsure, just rename the file to Exports.old and see if your issues vanish. Then we can work from there.
- Disable Windows Game Mode.
- In your Nvidia control panel:
   - Make sure that Threaded Optimization is turned on (not auto) for your DCS World profile. We've seen some suspects that auto is not fully working.
   - Enable the performance settings on the Power saving and Texture Quality values.
   - Set low latency mode to Ultra.

so (testing in 2d first) had a stutter fest and run the slow repair (no difference)

but in my nvidia control pane if I set my max frame rate to 1000fps and enable threaded optimisation seems to help and removes the 

stutter - however strangely using the fps counter (ctrl+pause) at the top (in blue) it shows fps now as almost locked at 32 and T as zero and below

its say gpu bound with a "theor FPS of 1410"! - whats going on and what is my real FPS (it certainly does not feel like 32?)

[Special K]

vor einer Stunde schrieb mac22:

so (testing in 2d first) had a stutter fest and run the slow repair (no difference)

but in my nvidia control pane if I set my max frame rate to 1000fps and enable threaded optimisation seems to help and removes the 

stutter - however strangely using the fps counter (ctrl+pause) at the top (in blue) it shows fps now as almost locked at 32 and T as zero and below

its say gpu bound with a "theor FPS of 1410"! - whats going on and what is my real FPS (it certainly does not feel like 32?)

That 1401 is definitely a miscalculation somewhere. If it displays 32 as your FPS then your FPS are at 32. You can use the Nvidia overlay, if you don't trust the ingame display. 

[mac22]

2 hours ago, Special K said:

That 1401 is definitely a miscalculation somewhere. If it displays 32 as your FPS then your FPS are at 32. You can use the Nvidia overlay, if you don't trust the ingame display. 

its very strange as the 32 fps at the top (assume this is the current fps) looks like its fixed (almost as if there is a vsync on that locks your fps to 32!)

1)is there any setting that might cause this behaviour? (strangely with the thread optimization off the fps jumps around 60-70 but its a complete stutter fest).

2)where can I enable the nvidia fps overlay and will give it a try? (assume fraps will not work).

(edit this is all in 2d)

Edited April 15, 2023 by mac22

[Special K]

vor 4 Stunden schrieb mac22:

its very strange as the 32 fps at the top (assume this is the current fps) looks like its fixed (almost as if there is a vsync on that locks your fps to 32!)

1)is there any setting that might cause this behaviour? (strangely with the thread optimization off the fps jumps around 60-70 but its a complete stutter fest).

2)where can I enable the nvidia fps overlay and will give it a try? (assume fraps will not work).

(edit this is all in 2d)

 

Overlay can be activated in the GForce Experience Overlay. You usually get that with pressing ALT+Z (might be Y depending on the language of your keyboard).

And there are some things that can limit FPS. Disable any VSYNC in DCS and the Nvidia control panel, make sure you didn't limit the FPS in the control panel.

If unsure, send your settings. I'm more responsive in discord, if you get to the help channel btw