What I updated Fallout to version 1.3 I was expecting things to be running smoother, not worse. The issues started when AMD released their new drivers, which added a Crossfire profile for the game, however, this patch worked with Fallout 1.2 and the release of both updates on the same day created many more problems than they resolved. The big one was dire gaming performance in Crossfire, despite having the profile enabled as well as invisible textures, severe glitching, flickering and more.
A batch file was made by a Steam user which helped revert the game to version 1.2, thus allowing the use of Crossfire again, but that’s hardly what I would call a fix. Thankfully, AMD has now released their 16.1.1 Hotfix driver, which combats the flickering issue and should clear things up nicely.
Article Number: RN-WIN-RADEONCRIMSON16.1.1HOTFIX
This article provides information on the latest posting of the AMD Radeon Software Crimson Edition 16.1.1 Hotfix Driver
The AMD Radeon Software Crimson Edition 16.1.1 Hotfix Driver contains the following:
AMD Radeon Software Crimson Edition 16.1.1 Hotfix Driver Version 15.301.1801
The AMD Radeon Software Crimson Edition 16.1.1 Hotfix Driver can be downloaded from the following links:
 Fallout 4 – Flickering may be experienced at various game locations with the v1.3 game update and with AMD Crossfire™ enabled. The AMD Radeon™ Software Crimson Edition 16.1.1 Hotfix driver has been updated. Please download this driver once again and reinstall it to address this issue.
If you’re going to update and you’ve got things working pretty well already, be sure to create a restore point so you can revert if it all goes to hell. The new Hotfix should fix the issue for you, it did for me, but there’s always going to be that small percentage where it likely makes things worse, although this is true of any update.
You can find all the information on the new drivers on the official AMD page right here.