Originally, you could change the DirectX renderer with the old launcher. This was quite necessary, especially on newer PCs, to use DirectX 11 instead of 9, because on DirectX 9, the game could actually run worse thanks to stuttering, unless the -str command line was used; DirectX 11 would make the game run fine thanks to its improved multithreading support the API provided, without being required to use -str.

However, with the 2021 update, the launcher was completely removed and replaced with the Rockstar Launcher. While changing the graphical settings is still possible ingame, changing the DirectX renderer is not. On default, the game runs on DirectX 9, meaning you could encounter performance issues.

Nevertheless, it is still possible to change the renderer by simply editing the settings.ini

Firstly, you need to locate the settings.ini file. It is in Documents/Rockstar Games/L.A. Noire.

Then open it. The DirectX Renderer is the penultimate line of the file:

Simply replace "DirectX 9" with "DirectX 11", then save the file.

And that's pretty much it! Now the game should run on DirectX 11 with no stuttering whatsoever.

Note: If your PC does happen to have problems running the game on DirectX 11, revert it to DirectX 9. You should also consider changing the Threading setting from "Multi" to "Single"

Note 2: If you also wish to change the language, simply replace "English" with what you wish to be displayed as. For example, if you want German, replace "English" with "German".