Wake and Speed Acceleration cause drop of CPU usage

[Shadow KT]

Here is my problem and I would like to get more insight on it....

 

When having a lot of aircraft flying close together with wake enabled, CPU usage would drop to 50-55% and GPU usage would drop down to as low as 20% and my FPS would tank.

 

Accelerating time has the same effect.

 

When disabled (wake), game runs smooth.... FPS still drops with a lot aircraft, but no where near as much and the game stays smooth...

 

With wake/time accelerate and drop of CPU and GPU usage, FPS would tank down to 10. When disabled FPS drops down to 20-30 FPS only, but the game stays smooth and usage is in norm

 

Could this have to do with RAM/Page File usage ?

 

i5 3570K @4.5

1070

16GBs of RAM

DCS on a SSD, with maximum preload and plenty of space for a pagefile

[Worrazen]

Wake turbulence may not be optimized yet but I don't know about it enough.

 

Acceleration lag is normal behavior. Depends on your CPU, don't expect it to ever be smooth unless you install 1 extra CPU each time you raise the game speed by 2 times :P

 

Acceleration may improve after Vulkan API and *multi-threading* update.

 

16GB feels a bit like it's not enough RAM for what you're saying is a lot of planes. Get an overlay (MSI/RSST, GPA, etc) going that will keep a check on Commit Charge so you could see if you're going over the RAM amount (16384 MB) that means you're paging out some of the memory to Pagefile, unused memory is paged out ofcourse so if it's only a little bit it probably isn't hitting DCS that much but that can depend.

Edited March 4, 2020 by Worrazen

[Shadow KT]

You missed my point....

 

What I am trying to bring attention to is the drop of usage, combined with the lowered performance.... one would thing that, if you need more performance, your hardware will be working harder, not less....

 

I've also had bugs in the past where I would get the same in MP, unless I do a restart...

 

I have no stutters and issues with RAM/Pagefile. I've allocated plenty for it to use on one of my SSDs

[Worrazen]

Sorry, your CPU usage falls down because the GPU can't keep up in GPU bound cases and so the CPU can't give the GPU that much work, and because the legacy GFX APIs depend on CPU spoon-feeding the GPU.

 

Another way is that the CPU is busy with some part and other things wait for that to finish so the CPU can't feed the GPU and since GPU is dependant it also falls down in FPS.

 

Vulkan API and newer APIs deal with graphics work differently, they do proper multi-threading, async compute, it makes graphics much much less dependant on CPU.

 

Acceleration is just ... it's more of a hack in a way, I tend to avoid it completely when troubleshooting or performance testing.

[Harker]

When you say your CPU falls to 50%, do you mean the specific thread that DCS is primarily running on? If you're getting stutters or low FPS, something must be maxing out. Can you post a screenshot of your CPU (per core), GPU and RAM usage?

[Worrazen]

I don't think I said anything about "50%" specifically, everything was meant in general, I haven't tested anything yet around this issue.

 

Depending on your activity within DCS, different components will take different amount of CPU mostly from the one thread, if that one CPU can't keep up it may even stall out the whole process and thus introduce stutter because of the process it self is being frozen and it doesn't really matter what FPS is or can be at that point of the execution is stopped.

 

There's many types of stutters, CPU, GPU, File I/O, ... there's a thread I was trying to finally complete about the File I/O terrain loading and threading, but it's it's own thing that's not directly related to other issues, but it is related to overall performance experience.

 

Bah, I thought you were the OP talking to me ... the explanation still relevant tho.

 

So if the Wake adds a level of logic, it may take a big chunk to put the CPU usage over the edge in that scene with a lot of aircraft == a lot of airplanes interacting with a lot of wakes.

[Harker]

Yeah, I was asking the OP about their 50% CPU usage. I agree with what you're saying, that's why I asked the OP for a more detailed description. I often see people talking about general CPU % use, without taking separate cores/threads into account (ie my CPU is only at 50% and then you see that one of the four cores is pegged at 100%, while the rest are at 33%). Or it could be something else that's hitting its limit.