During a long time i had lag/frozen screen problems on some tracks (Long Beach 2007,Sebring Int. Raceway,Suzuka 2012,...) or with some mod (DTM) and it was very annoying because This had a big impact on my competitiveness during race.
I know it wasn't a problem with my pc as it is powerful one but problems with the settings of GTR2 and elsewhere.
Finally one day i found the solutions and from this moment i didn't have any frozen screen/lags problems.
I write this post today to share my experience and help anyone who have this problem (Ogurchik on the Nos).
There is 2 fix to do to solve this issue (actually possibly 3 fix).

1st Fix (The easiest)
Run GTR2, Options / Advanced / LEVEL OF DETAIL BIAS Put it to 75%.
You can also change it manually without going InGame by changing your *.PLR (for example : C:\GTR2\UserData\YourNickname\YourNickname.PLR)
LOD Multiplier Multiplier="0.75000"
By Default the value is "1.00000"
I did not really see changes on graphics while racing but probably it has.

2nd Fix (a little bit more complicated)
In GTR2 (also GTLegends) there is a problem with the antialiasing/anisotropic settings as they are basic/outdated and doesn't manage advanced AA/AF that you have got with recent nvidia/AMD panel.
(Source : https://www.overtake.gg/threads/how-to-install- gtr2-and-png3-in-2019.173928/ ).
In your GTR2config.EXE (choose 32bits resolution, dx9) but Do NOT choose AA/AF (level 1/2/...).
If you have a Radeon Graphic card you will have to install RadeonMod (i don't have one Radeon graphic card so i can't tell how to replace/override application setting for AA on RadeonMod)
If you have an Nvidia Graphic Card You will have to install Nvidia Profile Inspector https://github.com/Orbmu2k/nvidiaProfileInspector/ releases
Run nvidiaProfileInspector.exe (with Administrator rights "it is always better" )
Make a save of your original GTR2 nvidia profile : "export current profile only" / "GTR 2.nip" choose a place on your HDD / Save.
In Profiles (Top Left), Type "GTR" and choose GTR2
1 - Compatibility
Antialiasing - Compatibility (DX9) - "change to" Diablo III (0x004412C1)
2 - Sync and Refresh
(optionnal) Frame Rate Limiter V3 - "my config" 150 FPS (Only if you have lots FPS while you play example more than 300 FPS) or leave it "Off"
3 - Antialiasing
Antialiasing (MSAA) - Mode - "change to" Override any application setting
Antialisaing (MSAA) - Setting - Application-controlled / Off ( you can improve your graphics by changing this to 8x or 16x or else but you can also have FrozenScreen/lag again so better to keep it to "Off" )
4 - Texture Filtering
Anisotropic Filtering - Mode - "change to" User-defined / Off
(optionnal) Texture Filtering - Negative LOD bias - "Allow"
At the top Right click on "Apply Changes"

3rd Fix (maybe not necessary but improve a lot the performance of GTR2)
GTR2 use only 1 core of your CPU while you play but you can install a software (free) to make GTR2 use ALL your cores of your CPU.
Download and install "Process Lasso" https://bitsum.com/get-lasso-pro/?inproduct
Run ProcessLassoLauncher.exe (with Administrator rights "it is always better" )
Everytime you run Process Lasso you will have a commercial window and have to wait to open the software but in fact you just need to click on "buy now" and then to close the internet window.
That's all you have to do to open quickly Process Lasso without buying it and you could also updated it without buying it. if you want to buy it of course you can.
In Process Lasso, Choose "Parameters", "CPU", "CPU Affinity"
Processus Match you type "gtr2.exe" without "
Affinity CPU , click on Select, then click on ALL (select all your cpu), then click on "OK"
For my part i have chosen all my 15 CPU cores but of course you can decide how many to choose. I never had any problems even if i have chosen all my 15 CPU cores.
Normally you will see in the window "gtr2.exe / 0-15" (if you have chosen 15 CPU cores)
That's all for Process Lasso.
Of Course before launching GTR2 you will have to open Process Lasso and thanks to this software GTR2 will use all your cpu cores while playing and it will really improve the performance of the game and probably avoid some issues or crash.

That's All !

I must say i play GTR2 on 3 screens with a resolution of 11520X2160
In GTR2 i have all my video options on Maximum (except "Shadow - High" ), 30 Vehicules Visibles.
I use the XD with the track map while racing.
Since i made theses fixes i never had again LAG/Frozen screen with any mods or on any tracks.
I can also say i didn't have any "crash game" in 2 years of racing on Kolschbierbude (except 1 on Zandvoort 2020 with Porsche mod which make me think it is a bug in the track)
I hope this post could help.

Salut Nicolas

Incroyable, tu es ingénieur ? Bravo, tout le contraire de moi, je ne comprends rien !! LOL

jackpot

satanas27 wrote:
1st Fix (The easiest)
Run GTR2, Options / Advanced / LEVEL OF DETAIL BIAS Put it to 75%.
You can also change it manually without going InGame by changing your *.PLR (for example : C:\GTR2\UserData\YourNickname\YourNickname.PLR)
LOD Multiplier Multiplier="0.75000"
By Default the value is "1.00000"
I did not really see changes on graphics while racing but probably it has.

--------------

About 1st Fix, it is a bit extreme to change "LEVEL OF DETAIL BIAS" directly from 100% to 75%.
The most Important about lag/frozen screen is the 2nd Fix.
If after applying the 2nd fix for some track/mod you have sometimes lag then you can low the "LEVEL OF DETAIL BIAS".
For Myself after applied the 2nd Fix i had no lag again during a long moment since it happened once for the track "Le grand Sambuc" and i was at 100% "LEVEL OF DETAIL BIAS". So i lowed to 75% and since March 2024 I had no more lag. I will made some test and try to put it higher around 85% to see if it sill goes well.
Anyway i admit i did not really see any differences with the graphics.

Thanks Nick.