The Epic Games version requires an additional step because Epic encrypts and alters the executable. You must download the Epic Games Patcher from Nexus Mods first to downgrade the executable to a mod-compatible Steam state before applying the memory patch.
While the 4GB patch fixes the memory ceiling, Fallout: New Vegas requires a "trifecta" of fixes to run perfectly on Windows 10 and 11. fnv 8gb patch fix
Go to the Nexus Mods website and search for "FNV 4GB Patcher" (Mod ID 62552). Click the "Files" tab and manually download the latest version. The Epic Games version requires an additional step
In a 32-bit operating system, an application can only address a maximum of 2^32 bytes of memory, which equals 4 Gigabytes (GB) . However, the Windows operating system reserves half of that address space for the kernel (system processes). This leaves the game with access to only 2GB of Random Access Memory (RAM) . Go to the Nexus Mods website and search
The extended version of the Script Extender, xNVSE , includes significant memory improvements.