Arnold Preferences - Arnold for Maya
You can find Arnold-related options in the Arnold category of the Maya Preferences (Windows > Settings/Preferences > Preferences).
Create Denoiser
Disable (or enable) the creation of a default Arnold denoiser (OIDN) in new scenes.
You can override the Create Denoiser preference with the ARNOLD_DEFAULT_DENOISER environment variable. Set it to false, off, or 0 to never create a default denoiser in new scenes, and to true, on, or 1 to always create a default denoiser.
Enable Global Snapshots Folder
The snapshots folder is where the snapshots are saved to disk. The default snapshots folder inserts a subfolder with the scene name. If you change projects, you can choose to copy or move the snapshots (when Use Snapshots Folder is enabled).
This global option overrides the Use Snapshots Folder behavior in the Arnold RenderView window, which is saved with the current scene.