The 4GB patch for Fallout: New Vegas is a tool used to load the game with the Large Address Aware executable flag which is used to allow the game’s executable to use 4GB of Virtual Memory Address Space which can actually stopped the “Out of Memory” error from appearing. Also, there is another helpful mod which can be used to solve the problem. The cause of the error is usually the fact that the game is somehow unable to use more than 2GB of RAM by default and it needs to be changes using mods.

What Causes the ‘Out of Memory’ Error on Fallout