DCS insists on using single core

[deltaleader]

In one of the last few updates, something changed with how DCS is using multi threading. I have tested on two different systems and each one exhibits DCS loading up one core and not utilizing other CPU cores. I have a new system setup now and it behaves the same way. I have tried the normal DCS World shortcut to launch the program as well as the DCS World MT shortcut. Both insist on utilizing core 1 in this case and very little of the other cores. This prevents me from getting in to a session. 

My work around at the moment is to use process lasso and block DCS from using core 1. That seems to help quite a bit. My question is, what is going here? Is this a bug or is something misconfigured?

 

Side note: It is possible this started after Windows 11 was installed, but I am not totally sure. I have done clean installs of everything and driver updates. Nothing helps.

[BIGNEWY]

Please attach your dcs log and dxdiag it should help us diagnose what is going on. 

thank you 

[Rudel_chw]

15 minutes ago, deltaleader said:

In one of the last few updates, something changed with how DCS is using multi threading. I have tested on two different systems and each one exhibits DCS loading up one core and not utilizing other CPU cores.

 

I dont see this problem on my PC, which is on the latest DCS version:

 

 

but I'm still on Windows 10, so maybe its a Win 11 issue only.

[deltaleader]

Let me know if this dcs log is good or not. I can try to reproduce the problem and create a new log. This was from my last session. The more I think about this, I think the problem started happening on Win11 but cannot totally confirm that other than it happens on 2 different machines running Win11.

dcs.log DxDiag.txt

[Rudel_chw]

33 minutes ago, deltaleader said:

Let me know if this dcs log is good or not

 

Only thing I see different from my system, is that yours has this warning:

 

"WARNING EDCORE (Main): hypervisor is active"

 

Are you running DCS inside a Virtual Machine?  a rented server maybe?

[scommander2]

For 265K, P-Cores are not sequential likes 12/13/14th gen by checking the 200s "Compute tile Floorplan".  The following is not sure:

2025-03-15 02:26:06.669 INFO    EDCORE (Main): common cores: {7, 8, 18, 19}
2025-03-15 02:26:06.669 INFO    EDCORE (Main): render cores: {1, 9, 0, 6}
2025-03-15 02:26:06.669 INFO    EDCORE (Main): IO cores: {2, 3, 4, 5, 10, 11, 12, 13, 14, 15, 16, 17}

according to dcs.log.

All P-Cores are used in either common/render cores...

 

Edited March 15 by scommander2

[deltaleader]

I am running this on a new machine I built using a MSI MEG ACR Z890 with Core Ultra 7 265k and 64GB of RAM. All on a new install of Windows 11 Home. The whole P and E core thing is new to me. I did not set up any overclocking in the bios or than setting my memory to XMP profile. I am not sure what is going on with Hypervisor. I did not install any VM's unless Win11 does something by default. I checked my Windows features and Hypervisor is not installed nor is virtual machine platform.

I can say when the problem comes up trying to load in to a plane in DCS, one core is pegged and the others are under light use. This also happened on my previous machine using Win11 with an I9-10900X CPU. Once I kill the pegged core with process lasso, everything loads right up. I have seen some other threads here saying to toggle it on and off does the trick. For now I can kill the one core but it would be nice to not have to do that and figure out what the root of the problem is. I appreciate everything looking in to this.

Edited March 15 by deltaleader

[scommander2]

What happened if without PL:

2025-03-15 02:26:09.324 WARNING APP (Main): ProcessLasso is running

And, manually set process affinity by using Task Manager->Details (looking dcs.exe), right mouse button click for "set affinity" for selecting all P-Cores (0, 1, 6,  9, 7, 8, 18, 19).

A good sign is that no CPU core parking is shown in dcs.log  

Edited March 15 by scommander2

[deltaleader]

When I don't run process lasso, I can never load in to a plane. Here is what my CPU looks like with out process lasso.null

I can alt-tab out and launch process lasso and the core recovers, game loads.

[scommander2]

How about the following thread?

 

 

[deltaleader]

28 minutes ago, scommander2 said:

What happened if without PL:

2025-03-15 02:26:09.324 WARNING APP (Main): ProcessLasso is running

And, manually set process affinity by using Task Manager->Details (looking dcs.exe), right mouse button click for "set affinity" for selecting all P-Cores (0, 1, 6,  9, 7, 8, 18, 19).

A good sign is that no CPU core parking is shown in dcs.log  

So I set the core affinity as you described, no process lasso. Launched game, loaded in to a multiplayer server. Just those cores selected were being utilized but none of them were just 100%. Plane loaded relatively quickly.

Are those cores considered the P cores that game should be using? I know when I just blocked core 1 that was getting hit initially, everything was fine. I suspect I can just use process lasso for DCS and workaround this problem as I have been doing. I also tried to turn off core isolation in windows, but that did nothing.

9 minutes ago, scommander2 said:

How about the following thread?

 

 

I don't or cannot find core parking enabled or referenced in my settings per that thread.

Edited March 15 by deltaleader

[scommander2]

10 minutes ago, deltaleader said:

I don't or cannot find core parking enabled or referenced in my settings per that thread.

My win 11 does the core parking enabled, so I had disabled it.  And, I did not find the warning message of the core parking in your dcs.log.

18 minutes ago, deltaleader said:

Just those cores selected were being utilized but none of them were just 100%. Plane loaded relatively quickly.

Is it okay so far?

[scommander2]

On 3/15/2025 at 5:33 PM, deltaleader said:

I checked my Windows features and Hypervisor is not installed nor is virtual machine platform

Intel-VT can be disabled from BIOS if the option is available.

[deltaleader]

Sorry haven't messed with all this until today again. I will check for Intel-VT. Not sure if my Intel Ultra Core 7 has this or not. Everything seems different with the Z890 chipsets. But for the most part, DCS is pegging CPU 1 at 100%, other cores are fine. My only real solution at the moment is process lasso which fixes the problem by locking out DCS from CPU 1. Performance seems ok when doing this, so I can't really complain about this workaround. 

[scommander2]

Checked Intel 256K spec, the CPU has the feature and it is up to BIOS to enable or disable.  Regardless, disabling VT just make sure the CPU/memory has less impact to DCS.  

Opted out CPU 1 means one P-core is unusable for DCS, and it is interesting finding...

If I get 285K, will I have the same issue?!

 

[T.Power]

I was curious about this thread so I thought I'd check my system to see what happens, sure enough when I load a mission one of my CPUs max out, but if I turn affinity to off and then back to all it fixes it.  Ryzen 9 6900HX if that helps.

[scommander2]

I guess that the treatment is different between Intel and AMD. 

[deltaleader]

I don't know if this is a Win11 bug or DCS. At the very least I would hope DCS would investigate this problem. There are workarounds which makes me think it's more of a bug. I am guessing it would happen on the the Ultra 285K processor as well because it was happening on my old 10900X processor but only after I updated to Win11 or a DCS update in the last couple of months. Just not sure exactly when it started other than those two changes. When I was on Win10, I didn't notice this problem, although it could have been present. 

[Leg2ion]

One question. How does core parking tie up with C states - if at all?  If you disable C States in the BIOS does this negate need to disable core parking etc (thinking core parking is a C State option/sub selection?).

Recently hit an issue with the Iraq map - flew out of Mosul no problems (low level Apache) - flew back in and what I would call the 'micro-stutter' that was prevalent a few years ago had re-appeared. Admittedly first time using the Iraq map so unsure if it is the map as have no issues on any other maps. Disabled core parking and the stuttering was awful - down to (rough guess judged by what I saw!) around 1 FPS!