4GB Patch

From Morrowind Modding Wiki
Jump to: navigation, search

4GB Patch
Requirements 64-bit OS and more than 4GB memory
Download N/A
Website Homepage

The 4GB Patch is a tool that patches any x86 executable so that it can access 4GB of memory instead of just 2GB. This patch should only be used by users with a computer that has a 64-bit OS and more than 6GB of RAM. This is particularly useful for players who are looking to use many hi-res texture packs.


While 32-bit applications have the capabilities to access up to 4GB of RAM, they are in fact limited to just 2GB. This is because the other 2GB is reserved by the OS. Even while running the application on a 64-bit OS with more than 4GB of RAM, the application is still limited to just 2GB.

Explanation from NT Core's homepage:

I originally wrote this tool for a friend of mine who needed it. This very little tool patches x86 executables in order to let them have 4GB (instead of only 2) of virtual memory on x64 platforms. This tool comes very handy for applications which need a great amount of virtual memory like games, 3D renderization, multimedia etc. To gain these 2GB, you just have to use this tool to patch the executable (*.exe file) of the software you want to have these additional GBs of virtual memory. It can be used by clicking on it and choosing the file or through command line (e.g.: "4gb_patch file.exe"). It automatically creates a backup copy of the original executable.

Why things are this way on x64 is easy to explain. On x86 applications have 2GB of virtual memory out of 4GB (the other 2GB are reserved for the system). On x64 these two other GB can now be accessed by 32bit applications. In order to achieve this, a flag has to be set in the file's internal format. This is, of course, very easy for insiders who do it every day with the CFF Explorer. This tool was written because not everybody is an insider, and most probably a lot of people don't even know that this can be achieved. Even I wouldn't have written this tool if someone didn't explicitly ask me to.


Simply run 4gb_patch.exe. An open file dialog will open and from here you can navigate to your game folder and open Morrowind.exe. The patch will automatically run, create a backup, and ask if you want to patch another application. Just click the Ok button to close the patch.

External Links

NT Core's Homepage