Severe loading performance issues with 2.9.15

[Nightstorm]

Both the first and hot fix 2.9.15.9509 have severe loading performance upon loading a mission into the mission editor and starting the mission.  Sound/music skips and the game is also slow to exit.  The issue does seem to improve after a bit and you can load missions faster.

Restoring to 2.9.14 corrects this issue with no other changes.

[scommander2]

@Nightstorm, thanks for posting and I am glad that I am not only one felt the performance issue after patching DCS  

However, I am wondering that will the new patch does not impact who have better/best hardware?

Edited Tuesday at 02:08 PM by scommander2

[speed-of-heat]

honestly mines better after the hotfix!  Though it is slow to exit. 

I think this is one of the reasons that DCS is such hard work for ED to diagnose problems like these

[scommander2]

I guess that the patch has no impact for users who have the topnotch hardware.

[speed-of-heat]

no because i had intermittent albeit mild stutters on the previous release...

[sleighzy]

@Nightstorm, attach your DCS log file after replicating the issue.

[Nightstorm]

2 hours ago, sleighzy said:

@Nightstorm, attach your DCS log file after replicating the issue.

I was building a quick test mission here and going back and forth between two missions.  The performance improved after the initial loading but it seems to hang on terrane initit for a good bit of time.  Starting up and shutting down takes longer than 2.9.14.

dcs.log

[sleighzy]

Wow, you win the award for most mods I seen yet  The log is spammed with a bunch of errors for those. I'd recommend temporarily removing those and running a slow repair of the game. Even though they may not be used in a mission they will still be loaded. Delete your Saved Games\DCS\fxo and metashaders2 caches after this as well so that the cached textures are fresh and no old cruft is being loaded. Initial load time when it first recompiles those may increase, but all good afterwards. This will at least get you to a clean state and rule any of that out.

I ran this log through the DCS log analyzer which confirmed a few things I saw in the log. You appear to be applying an affinity mask to this process, I don't see it in the process args but maybe either registry, Process Lasso (?), or somewhere else. You've basically prevented half of your CPU from being used. I'd remove that as well.

system  affinity mask: 11111111111111111111111111111111
process affinity mask: 1111111111111111
CPU: Intel(R) Core(TM) i9-14900K [1x L3 caches]
CPU has uniform cache size 36 MB (per cache)
all CPU cores have the same efficiency class 1
CPU cores have different performance classes: [1-2]
logical cores with performance class 2: {4, 5, 6, 7}
logical cores with performance class 1: {0, 1, 2, 3, 8, 9, 10, 11, 12, 13, 14, 15}
common cores: {8, 9, 10, 11, 12, 13, 14, 15}
render cores: {4, 5, 6, 7, 0, 1, 2, 3}
IO cores: {}
unavailable cores: {16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31}

Dropping your preload radius down (currently max of 150000) may also help with loading times and reducing VRAM/RAM usage.

You can also update your shortcut to run DCS from the bin directory vs. bin-mt now. They're both multithreaded and bin-mt will be removed in the future. Also prevents chances of other errors users have hit with this.

Try the above and see what happens. The performance improvement after initial load is potentially all the assets have been cached at that stage, although not permanently.

Note that the above are not guarantees, but will at least rule out a number of factors. DCS is becoming smarter around the way it manages it's CPU core usage so potentially additional changes in these latest releases. For example, it may use the E-cores for I/O thus freeing up your performance cores from performing this work.

I'll see if I spot anything else in here, but would be good to get another log with this issue but without all the mod errors and in a known state to filter out the noise and see what happens with your CPU.

Edited Wednesday at 01:21 AM by sleighzy

[sleighzy]

I also noticed that you were loading into Germany Cold War. Does this happen on other maps as well?

[scommander2]

1 hour ago, sleighzy said:

IO cores: {}
unavailable cores: {16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31}

I am wondering that not few E-Cores were used by IO Cores, intertesting. 

[scommander2]

22 hours ago, scommander2 said:

I am not only one felt the performance issue after patching DCS

I found out that my HDR was enabled for some reasons, it was much better after I disabled it.

[Nightstorm]

11 hours ago, sleighzy said:

I also noticed that you were loading into Germany Cold War. Does this happen on other maps as well?

Thank you for the information.  I did try it w/o process lasso, but I hadn't tried it yet with zero mods since the same mods (although not updated for 2.9.15) were running under 2.9.14 w/o issue.  But I will try that.  The issue was happening on other maps too beyond the new Cold War map.

Thanks for the information on the BIN vs BIN-MT, I didn't know that they were both multi-threaded now.  I was gone for all of 2024.  I missed a lot.

[scommander2]

3 minutes ago, Nightstorm said:

Thanks for the information on the BIN vs BIN-MT, I didn't know that they were both multi-threaded now

They are same.

4 minutes ago, Nightstorm said:

I did try it w/o process lasso, but I hadn't tried it yet with zero mods since the same mods (although not updated for 2.9.15) were running under 2.9.14 w/o issue.  But I will try that

Process Lasso is not required anymore for the most recent DCS version, instead it causes some issues according to some users.

[Nightstorm]

5 hours ago, scommander2 said:

They are same.

Process Lasso is not required anymore for the most recent DCS version, instead it causes some issues according to some users.

Does it cause issues only if you apply an affinity to DCS.exe?  Or if it's installed in general?

[scommander2]

13 minutes ago, Nightstorm said:

Does it cause issues only if you apply an affinity to DCS.exe?  Or if it's installed in general?

I think PL does something more than just applied the CPU affinity.

According to the attached dcs.log:

2025-04-22 22:45:39.244 WARNING APP (Main): ProcessLasso is running

Sorry, I missed this one  

However, I am still interested that DCS simply ignores all E-cores for its IO core usage... Is it caused by PL?

Edited Wednesday at 07:23 PM by scommander2

[Nightstorm]

Yes, I had the affinity set to only use P-Cores.  I was running a lot of other background stuff on the E Cores that doesn't need high performance like One Drive, Dropbox, etc.

[scommander2]

15 minutes ago, Nightstorm said:

the affinity set to only use P-Cores

Okay, it explains why dcs.log said:

system  affinity mask: 11111111111111111111111111111111
process affinity mask: 1111111111111111

all cores are available for dcs.exe but dcs can use P-cores only.

In my opinion, if we can disable PL for once to try out.   

[Nightstorm]

I've done what was asked above.  PL is disabled/not running.  No mods, not even a livery file.  Cleared shaders and rebuilt.  Simple test mission with a viper at Nellis, no other units.  A full repair was completed and removed any extra files.

Running out of the BIN folder not BIN-MT.  Issues persist.  Slow loading mission editor, slow saving changes in ME and slow loading missions.

Log attached.

dcs.log

Edited Wednesday at 08:02 PM by Nightstorm

[scommander2]

This entry and related log have been removed from discord completed.

 

Edited Wednesday at 08:15 PM by scommander2

[scommander2]

FYI: one user also complained the related issue (may not be same).  He ran the GPU stress test, and he got very low FPS from GPU. 

[akinilgun]

Hello, after I updated to DCS 2.9.15.9408, I also get the error that freezes and does not respond immediately after the flight starts. So I can't use it at all after the update. How can I revert the update to DCS 2.9.14.8394? I'm waiting for your help. Thanks in advance.

[sleighzy]

2 hours ago, akinilgun said:

Hello, after I updated to DCS 2.9.15.9408, I also get the error that freezes and does not respond immediately after the flight starts. So I can't use it at all after the update. How can I revert the update to DCS 2.9.14.8394? I'm waiting for your help. Thanks in advance.

Open a command prompt within the DCS\bin directory and then run the below command (all one line). Delete your Saved Games\DCS\fxo and metashaders2 folders afterwards so that it rebuilds the texture caches again for that version. 
 

DCS_updater.exe update 2.9.14.8394@release

 

Edited Thursday at 01:54 AM by sleighzy

[Kiwi_Viper]

yeh its been bad for months taking longer and longer but mostly on first launch (and its NOT mods i took em out to try it no difference what so ever) once your in its fine i think its been worse sine they got rid of the two version, st and mt but hopefully itll improve as time goes on it seems stable enough just bloody slow

[scommander2]

8 hours ago, Nightstorm said:

Slow loading mission editor, slow saving changes in ME and slow loading missions.

What were the CPU/GPU utilization then?

I have tested with affinity with P-Cores only v.s. affinity with P/E-cores (default by DCS), they were not too much different on my 12 P-Cores and 8 E-cores.  Beside, ME runs with the CPU bound in the most of time (my CPU was about 28%, GPU was around 20% for 4080).

While played around NV driver, and I got my display refresh rate become 30 MHz (not sure) so my FPS was low around 30 (hope it is not a case).

[Mainstay]

Same problem here. Loading takes ridiculous long.. especially MP. 
 

I did a slow repair, disabled mods, deleted FXO and meta folders. 
Excluded everything in my AV DCS related. 
 

All this on a high end pc (12900K, 64gb ddr, 4TB nvme, rtx4090, win11, pimax crystal) 

It’s getting frustrating to be honest. Every other application or game loads up within seconds including flightsims except DCS. 
Also what’s up with the weird loading sequence screens on VR? Why can’t we see normal loading bars as if starting a session without VR. Half the time I can’t even see what the loading status is et cetera because it just hangs and you have to wait minutes for it to proceed to the next screen…