MT CPU Bound Renderthread, CPU Main Thread

[mac22]

On 3/21/2023 at 12:51 PM, Grendel said:

I had same issue, but it seems to be resolved for me.

I enabled thread optimalization, and set MAX FRAME to  1000 .

Now, higher fps at high preset. averaging 60 fps on free flight syria with the f16,where as I was locked prior at 45 fps.

 No more cpu bound in red, instead gpu bound in green which makes more sense.

i9-9900K , 2070 Super 8 gb, 64 gb ram, 2x1tb nvme

 

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?)

[Stahlwolle]

My Framerate Indicator also shows CPU Bound (Main Thread). Framerate is under 72 on Quest 2 (VR) which would be maxframerate for the Quest2 depending on graphic settings. BUT it always shows CPU Bound (Main Thread) - i never saw GPU Bound.

Wondering about on 7900x with 64gb Ram and 4800 rtx - Emty map, one Unit - Freeflight. GPU at 85 % workload indicated by Win-Task-Manager. Can i assume this comes due the early state of the MT-Version or is this something which can be considered as "normal" and can be explained somehow?

Edited April 26, 2023 by Stahlwolle

[Stahlwolle]

Hey Guys,

a simple question came to my mind - maybe easy to answer?

Does "cpu bound" mean the CPU is "bounded" by gpu or does it mean the cpu is "bounding" the gpu?

i play in vr and getting "cpu bound" all the time where i would expect that my gpu should be the bottleneck due to me being the only unit on the map.

does somebody know and could tell me?

best regards and happy flying!

Edited May 5, 2023 by Stahlwolle
corrections

[Temetre]

Am 5.5.2023 um 08:46 schrieb Stahlwolle:

Hey Guys,

a simple question came to my mind - maybe easy to answer?

Does "cpu bound" mean the CPU is "bounded" by gpu or does it mean the cpu is "bounding" the gpu?

i play in vr and getting "cpu bound" all the time where i would expect that my gpu should be the bottleneck due to me being the only unit on the map.

does somebody know and could tell me?

best regards and happy flying!

Pretty sure "cpu bound" means the current bottleneck is caused by CPU. Aka the framerate is bound by the CPU, while GPU could deliver more frames.

And yes, the CPU bottleneck situation is quite strange indeed. I got big missions with hundreds of units and horrible frametimes, but flying solo I got only somewhat better frames.

Edited May 12, 2023 by Temetre

[Dangerzone]

On 5/5/2023 at 4:46 PM, Stahlwolle said:

Hey Guys,

a simple question came to my mind - maybe easy to answer?

Does "cpu bound" mean the CPU is "bounded" by gpu or does it mean the cpu is "bounding" the gpu?

i play in vr and getting "cpu bound" all the time where i would expect that my gpu should be the bottleneck due to me being the only unit on the map.

does somebody know and could tell me?

best regards and happy flying!

 

Your computer will always be either CPU Bound, or GPU bound. One will always be faster than the other, so CPU bound isn't necessarily a bad thing (it often means you're using very conservative GPU settings, or you have a great GPU). CPU bound would also mean you could increase your graphic settings until no longer CPU bound, and back off slightly until you're CPU bound again, and you can enjoy those extra graphics at effectivley 'no cost.

However - CPU bound can also occur with lots of scripting, AI, or otherwise, which can decrease performance. From the missions I've been invovled in designing and scripting - lots of radar activity appears to be a potential culprit of this too. 

It would be a bit more helpful if you're able to post your graphic settings, and  your PC spec's along with the frames or screenshot of the FPS in DCS to be able to give you more than an over-all indication.

[Stahlwolle]

Hello Dangerzone,

thanks for your reply which i saw today - well - the question was rather what the exactly meaning of "CPU bound" is - does it mean CPU is bounding the system or does it mean the CPU could do more but it IS bound. I asked because i run the game in VR and have to run ridiculous resolution for barrel-correction and AA reasons - beside that with the specs more on the high - side - i posted in another topic screenshots of that. Yes the GPU is good (4080) and the System overall is good (7950x with 64gb ram).

So i tried to figure out some good settings by try and error and raised my settings until i saw some significant changes of the framerate. but as i did and saw the framerate dropping to 50-60ish the CPU bound message did not change which means that either my CPU was affected by my settings (which i am not think it could be a reason) OR it means my CPU is BOUNDED by Graphics card and has some potential. OR it means the CPU is limiting and the Message is wrong. I just wondered and i am not a native english-speaker (german) so i tought maybe someone could explain what CPU BOUND means exactly.

And it was a alone-on-map setup with no script and no other planes. Just me and the map. And some clouds.

 

best regards,

w

 

 

[Dangerzone]

18 hours ago, Stahlwolle said:

Hello Dangerzone,

thanks for your reply which i saw today - well - the question was rather what the exactly meaning of "CPU bound" is - does it mean CPU is bounding the system or does it mean the CPU could do more but it IS bound. I asked because i run the game in VR and have to run ridiculous resolution for barrel-correction and AA reasons - beside that with the specs more on the high - side - i posted in another topic screenshots of that. Yes the GPU is good (4080) and the System overall is good (7950x with 64gb ram).

So i tried to figure out some good settings by try and error and raised my settings until i saw some significant changes of the framerate. but as i did and saw the framerate dropping to 50-60ish the CPU bound message did not change which means that either my CPU was affected by my settings (which i am not think it could be a reason) OR it means my CPU is BOUNDED by Graphics card and has some potential. OR it means the CPU is limiting and the Message is wrong. I just wondered and i am not a native english-speaker (german) so i tought maybe someone could explain what CPU BOUND means exactly.

And it was a alone-on-map setup with no script and no other planes. Just me and the map. And some clouds.

 

best regards,

w

 

 

Fair question - coz I get the same results. My understanding is that the limit of the performance/frames is due to the CPU hitting it's limit (as opposed to the GPU). So the CPU has reached it's maximum potential in this instance. 

Whether the CPU can do more with BIOS settings changed, some windows services turned off, etc I don't think DCS would have a way of detecting. That would be up to you to optimize your PC. DCS is simply saying "I can't do any more because I've it the CPU or GPU limit - depending on which one is bound).

As for changing graphic settings dropping frames but still being CPU bound - yup - that happens with me too. My understanding is that the CPU still has to do a certain amount of work for GPU changes. I get the same thing. I can increase my graphic - such as the PD because my GPU is underutilized but I push it to a certain level and the frames will drop as a result, but it still says CPU bound. I'm guessing whatever work I'm asking it to do - the CPU is having to work a lot harder too (maybe shadows, or something that requires CPU resources?).

[Fulcrumkiller31]

I am running into the same issue. DCS says I am CPU bound, but it is hardly being utilized according to HWM (16-25%). Also my GPU is usually around 65-70%. After tweaking some NCP settings I am able to get a stutter free mostly smooth solution at 45FPS motion reprojected (OPEN XR, Fixed Foveated Rendering), I just cant help but wonder if I am leaving performance on the table. Also my frame times are 20ms which is ridiculous. 

Edited June 9, 2023 by Fulcrumkiller31

[Raven (Elysian Angel)]

I'm pretty sure this is an error in the code on ED's part. It's the same thing that happens in at least 1 other game I can think of: there is a certain free-to-play hack-and-slash game made by a company that's often referred to as 3x the same letter (trying to abide by the rule to not use other games' names) that also occasionally runs into this problem. CPU frametimes go from 1 or 2 ms to 24, jumping up and down and causing considerable stutter. There, it can easily be fixed by zoning to a different instance but you can't do that in DCS.
That same game also runs on Vulkan and uses a multithreaded client, btw.

For some reason the DCS stutters seem to be considerably less prevalent if I use native OpenXR with the command lines, than with the OpenXR toolkit, leading me to believe there is either an error or some sort of incompatibility with 1 or more lines of code.

[Nedum]

It has shown to me, if I use any kind of frame limiter, like MR in VR, I am by 100% CPU limited.

If I do not use MR in VR, I am GPU bound.

With a frame limiter, DCS MT becomes DCS ST. The CPU behaves the same way the !!old!! SC DCS behaves before. Only 1 Core is (mostly) doing all the work.

The behavior is the same with my old System (AMD 5900X, nV 3090 24GB VRAM, 32 GB RAM) and the new system (AMD 7950X3D, nV 4090 24 GB VRAM, 64 GB system RAM).

As soon, as I limit the FPS to a limit it can reach with ease, my system will be CPU bound. The interesting part is, the power which is unused will !!not!! be used for better graphics, if I raise them in the System Tab.

First off, my system should only be CPU bound, if the graphics are not the limiting factor. Second, I should be able to raise the graphics until they are the limiting factor again if I am using MR, but this isn't happening anymore. Once I limited my FPS with MR (Motion Reprojection), there is no way to use the unused GPU power anymore.

As far as I can see, there is a bug with MT and FPS limiting. I don't know if all VR people have the same problem, but I am definitely a victim of this behavior.

Edited June 11, 2023 by Nedum

[Buzzer1977]

On 3/10/2023 at 9:59 PM, =OPS=Slider said:

I've got the same problem. Ryzen 7 5800X, RTX 3080 and 64 RAM, with HP G2 as well. Same message, CPU Bound. Already ran a repair, removed all mods, deleted fxo and metashaders folders, to no effect.

Same here. 5950x, 128GB, RTX3090, HP Reverb G2 

[Raven (Elysian Angel)]

I was able to fix the CPU bound main thread/rendering thread stuttering by checking the option "prefer frame rate over latency" in the OpenXR Tools for WMR. I also need to keep the OpenXR Toolkit Companion App installed (default settings) or I have image flickering in my right eye (I no longer use OpenComposite).
It also took some experimentation in my Adrenalin settings to have the best performance, but now DCS is running better than it has in years


For those who use AMD: I have selected the Gaming preset in Graphics options within Adrenalin control panel, and made sure Radeon Enhanced Sync is OFF and VSync is also set to ALWAYS OFF.

[Buzzer1977]

On 6/22/2023 at 11:57 AM, Raven (Elysian Angel) said:

I was able to fix the CPU bound main thread/rendering thread stuttering by checking the option "prefer frame rate over latency" in the OpenXR Tools for WMR. I also need to keep the OpenXR Toolkit Companion App installed (default settings) or I have image flickering in my right eye (I no longer use OpenComposite).
It also took some experimentation in my Adrenalin settings to have the best performance, but now DCS is running better than it has in years


For those who use AMD: I have selected the Gaming preset in Graphics options within Adrenalin control panel, and made sure Radeon Enhanced Sync is OFF and VSync is also set to ALWAYS OFF.

null
Neither disabling motion reprojection, nor setting prefer frame rate over latency fixed it for me. Also tried with both, WMR and SteamVR as OpenXR runtime. No difference.
It's still CPU bound flickering between rendering/main thread.

[Buzzer1977]

I did some testing between WMR/SteamVR, ST/MT, 60/90Hz display setting and several aircraft on a naked map.
Best results i've got was when i used multithreading with WMR as runtime and limited the display refresh rate to 60 Hz.
The stuttering and switching between CPU bound main thread and CPU bound render thread always happend when i set the G2 to 90 Hz or when i used SteamVR and the AC wasn't a F-16 or F-18. It seems like DCS has some issues in VR when the display frame rate can't be achieved and the render and main thread fight over mutex locks. The stuttering can be seen in the graph below.

AC	ST 2D	MT 2D
	FPS	FPS	limit	theo. FPS
F-16CM	125	138	GPU bound	490
F-15E	110	122	GPU bound	380
F-18C	123	137	GPU bound	470
F-14B	108	121	GPU bound	310
AC	ST/VR(WMR) 60Hz	MT/VR(WMR) 60Hz			ST/VR(SVR) 60Hz	MT/VR(SVR) 60Hz
	FPS	FPS	limit		FPS	FPS	limit
F-16CM	55	60	CPU bound rendering		55	60	CPU bound rendering
F-15E	50	60	CPU bound rendering		50	45/60	CPU bound rendering/main thread	extremely shaky
F-18C	55	60	CPU bound rendering		55	60	CPU bound rendering
F-14B	50	60	CPU bound rendering		50	45/60	CPU bound rendering/main thread	extremely shaky
	ST/VR(WMR) 90Hz	MT/VR(WMR) 90Hz			ST/VR(SVR) 90Hz	MT/VR(SVR) 90Hz
	FPS	FPS	limit		FPS	FPS	limit
F-16CM	52/53	64	CPU bound rendering/main thread	shaky	53	56/60	CPU bound rendering/main thread	extremely shaky
F-15E	50	56/60	CPU bound rendering/main thread	extremely shaky	50	53/56	CPU bound rendering/main thread	extremely shaky
F-18C	52/53	64	CPU bound rendering/main thread	shaky	53	56/60	CPU bound rendering/main thread	extremely shaky
F-14B	50/51	60	CPU bound rendering/main thread	shaky	50	53/56	CPU bound rendering/main thread	extremely shaky

Edited June 27, 2023 by Buzzer1977

[Temetre]

Yeah this kinda stutter pattern is the biggest performance issue im seeing in DCS, and especially VR.

[Temetre]

Just wanna report back, I fixed almost all my performance, stutter, slow startup, VR and MT issues, just by reinstalling the game. 

Full repair didnt change anything, and I didnt need to touch my config files at all. Just clearing the DCS game folder and redownloading did it.

Maybe some files mustve gotten corrupted or so, and the repair tool couldnt fix it. 

 

Either way, those single spike stutters are gone in MT, VR+MT works perfectly fine now, and the framerate is much better in VR. Also, starting time of DCS went from ~2 minutes to 20 seconds.

Edited August 7, 2023 by Temetre

[WipeUout]

On 8/7/2023 at 3:05 PM, Temetre said:

reinstalling the game. 

Sounds like a pretty good fix, are you on steam or standalone?  Can you expand about "just clearing the DCS game folder"?  i.e. delete the folder directly or do uninstall through windows settings?

Edited August 15, 2023 by WipeUout
update

[Mobius_11804]

Well... I found a resolution.. Crank up all graphic-settings and capping the Framerate to 60fps.. runs buttery smooth like that xDD

[Buzzer1977]

On 9/1/2023 at 12:51 AM, Mobius_11804 said:

Well... I found a resolution.. Crank up all graphic-settings and capping the Framerate to 60fps.. runs buttery smooth like that xDD

Well, you've could have gotten these results 4 weeks earlier ...

On 6/27/2023 at 11:37 PM, Buzzer1977 said:

Best results i've got was when i used multithreading with WMR as runtime and limited the display refresh rate to 60 Hz.
 

 

 

[hazzer]

Hi all, I have just upgraded my pc (partially)

14700k 64gb, DDR5 6400mhz 

2080ti

To my surprise when I launched DCS it says I am still CPU bound. I have set the cpu affinity in project lasso to P cores only. Also my cpu usage is surprisingly low.

 

Any support on this would be greatly appreciated. I do plan on getting a 4090 soon, but if im already cpu bound im already at a loss!nullnull

[Dangerzone]

9 hours ago, hazzer said:

Hi all, I have just upgraded my pc (partially)

14700k 64gb, DDR5 6400mhz 

2080ti

To my surprise when I launched DCS it says I am still CPU bound. I have set the cpu affinity in project lasso to P cores only. Also my cpu usage is surprisingly low.

 

Any support on this would be greatly appreciated. I do plan on getting a 4090 soon, but if im already cpu bound im already at a loss!nullnull

Are you running Motion Reprojection? If so you will always be CPU bound, because Motion Reprojection will drop your frames further, ensuring that the GPU is rarely (if ever) running at capacity. The CPU bound doesn't mean that the CPU is getting cooked - it just means that you're not GPU bound because of the motion reprojection. Turn off MR and you'll probably see yourself go GPU bound at higher frames than you're currently getting.

[hazzer]

4 hours ago, Dangerzone said:

Are you running Motion Reprojection? If so you will always be CPU bound, because Motion Reprojection will drop your frames further, ensuring that the GPU is rarely (if ever) running at capacity. The CPU bound doesn't mean that the CPU is getting cooked - it just means that you're not GPU bound because of the motion reprojection. Turn off MR and you'll probably see yourself go GPU bound at higher frames than you're currently getting.

Unfortunately, I already have motion reprojection turned off. 

I was quite surprised that it's showing that the cpu is the limiting factor still. Looking at my frame time graph above my assumption is having all those jumps is not a good thing. This is also a completly clean install of DCS, so I am truly at a loss as to why performance isn't better. 

Edited October 30, 2023 by hazzer

[Dangerzone]

14 hours ago, hazzer said:

Unfortunately, I already have motion reprojection turned off. 

I was quite surprised that it's showing that the cpu is the limiting factor still. Looking at my frame time graph above my assumption is having all those jumps is not a good thing. This is also a completly clean install of DCS, so I am truly at a loss as to why performance isn't better. 

 

Have you gone through the optimization procedures. Things like ensuring that the clock speed is fixed/set above 5.0ghz (no throttling is going on), disabled HAGS, disabled CPU parking, RAM is running at optimum speed, etc? 

It does sound strange that it's CPU limited - but I know with my 13900K I had to do a lot of tweaking in order to get advertised speeds. Straight out of the box I think there's a lot of things (both BIOS and Windows based) that will severely hamper it's ability to perform at it's capabilities. 

[hazzer]

10 hours ago, Dangerzone said:

Have you gone through the optimization procedures. Things like ensuring that the clock speed is fixed/set above 5.0ghz (no throttling is going on), disabled HAGS, disabled CPU parking, RAM is running at optimum speed, etc? 

It does sound strange that it's CPU limited - but I know with my 13900K I had to do a lot of tweaking in order to get advertised speeds. Straight out of the box I think there's a lot of things (both BIOS and Windows based) that will severely hamper it's ability to perform at it's capabilities. 

Thanks for your response, so far I have:

Undervolted and limited the power draw of my cpu so it doesn't burn a hole through the floor. It is able to run at around 5ghz fully loaded. In DCS the cpu load isn't that big so it will be able to maintain 5.5ghz.

I'm using project lasso and enabled bitsum high performance which has prevented the cores from parking. One thing I'm not sure where DCS stands currently is hyperthreading on or off? 

The one thing I haven't yet done is HAGS off. Just going to try that now and will report back. 

It isn't like I haven't gone into this without trying to change settings and optimise the cpu. Just seems very surprising that it says this, I posted on reddit as well and it has been suggested that the overlay could just be wrong. 

I have a 4090 on the way tomorrow and I'm hoping that it does actually allow for some improvement. Fingers crossed. 

[hazzer]

nullHAGS disabled, It appears I now have higher FPS however the game is still bouncing between CPU bound, main thread and rendering thread. Given my gpu load is essentially between 97-100 I would think that it is still limited by the GPU. Anything else I can do to get the most out of my CPU in dcs?

Edited October 31, 2023 by hazzer