Multi-Core Fix for Fallout 3

Overview

A plain English guide to solving the biggest issue with Fallout 3.

READ ME FIRST BRO

Fallout 3 is buggy. Really buggy. This guide will probably help most users, but a lot of people are still going to suffer frequent crashes. There’s not much you can do about it beyond:

Installing the Unofficial Fallout 3 Patch: [link]
Installing the Fallout 3 Script Extender: [link]
Installing Cipscis’ Automatic Save Manager: [link]

The first download will reduce crash frequency, the second and third will help manage your save files and, if you set it up right, make it so you only ever lose 1 minute of progress at most during crashes.

Introduction

You might have noticed this on Fallout 3’s store page when you went to purchase the game:

This is actually a misnomer: Fallout 3 runs fine under Windows 7, and by extension, Windows 8. No, Fallout 3’s problem is that it isn’t optimized for processors that have more than two physical cores. When I say “not optimized,” however, what I really mean is “Fallout 3 will crash extremely often if you run it on a computer who’s CPU has more than two physical cores.” This is an especially odd quirk, considering the Xbox 360’s Xenon processor has 3 cores, and the Playstation 3’s Cell Broadband Engine has 8 cores. Even stranger, the bug doesn’t exist in Morrowind or Oblivion (which run on older versions of Fallout 3’s Gamebryo engine), was never fixed by Bethesda during the game’s patching lifetime, but was fixed for Fallout: New Vegas.

It was likely never fixed because the solution is incredibly simple.

The Fix

To fix the Multi-Core bug, one simply needs to edit a configuration file. The end result is that Fallout 3 will be limited to running under only 2 physical cores on your computer, and thus, not run into the bug! So really, this isn’t so much a fix as it is a workaround. Thanks Bethesda.

Here are the steps:

If you haven’t done so already, run Fallout 3 at least once. Once you get to the title screen, exit the game.
Open your Documents folder (My Documents in Windows XP), and inside, look for a folder called My Games. Inside should be a folder called Fallout3. Open this.
In this folder, open the file FALLOUT.ini with Notepad. Make sure the file is not read-only.
In the configuration file, search for the header called [General]. It will be at the very top of the file.
Go to the bottom of the [General] section, just before the [Display] header. The last line of the section should be sLanguage=ENGLISH, or whatever your language is.
Below this line, copy and paste the following two lines:
bUseThreadedAI=1
iNumHWThreads=2
Save your changes.

That’s it! You’re ready to play Fallout 3.

Conclusion

That’s all there is to it. This tends to be a problem for a lot of people the first time they run Fallout 3. If you have any questions or concerns, feel free to post in the comments below. I want to thank pcgamingwiki.com for the instructions on fixing this bug. I simply reproduced it here for the convenience of Steam users. You should go to this page for more bug fixes:

[link]

Tweak Guide’s page for Fallout 3 is also a great resource: