It's a user.ini file that changes the streaming object of the game to make it slower and to help with the stuttering. If you get 60+ fps while you're still standing but notice large drops while watching and moving, especially when driving, this can help. If you stand still and still don't have enough fps, then this mod probably won't do much since you're limited to the GPU.
One recommendation I would recommend is to use slow mode in the game options, even if you are using an SSD, this can massively help.

To install this mod, drop the file into "..\Cyberpunk 2077\engine\config\platform\pc".

Or create a new file named user.ini and add these lines:
[ResourceLoaderThrottler]
FloodMinNonLoadingThreads = 1
StreamMaxLoadingThreads = 1
TrickleMaxLoadingThreads = 1

[Occlusion]
BroadPhaseFraction = 1
DepthBufferDimScale = 6
FillphaseRangeFactor = 100.000000
MinBufferHeight = 1
MinBufferWidth = 1
MultiFrustumOcclusionMode = 0
MultiFrustumUseGlobalOcclusion = false
RastTilesJobGranularity = 1
TestPhasesCount = 6
[Rendering/MeshLoading]
AutoRefreshTime = 2.000000
LoadingDelay = 1

Some notes: You will notice stuff popping in the streets like garbage. This is not a bug, these changes are designed to slow down everything down, as the optimization of the game is not that great. If you do not like objects and textures to pop up, you can delete the user by uninstalling the user.ini file.

Credits:
throumbas