Fallout 4: the settings that actually cost you FPS
Godrays, Weapon Debris and shadow distance are not equal costs. Cut the three that matter and keep the Commonwealth looking right.
Fallout 4 is a 2015 game on the Creation Engine, which means most modern GPUs can run it — and yet downtown Boston still brings systems to their knees. The reason is not raw GPU power. It is three specific settings whose cost is wildly out of proportion to what they visibly add, plus a physics system that is tied to your frame rate.
The three settings that dominate the frame budget
Godrays come first. Fallout 4's volumetric lighting is GPU-intensive and affects stability more than almost any other option in the menu. Dropping Godrays from Ultra to Low or off is consistently one of the largest stability and performance gains available.
Weapon Debris is second, and it is not only a performance setting — it uses NVIDIA PhysX-based particle simulation and is associated with crashes on many modern GeForce systems. Turn it off before you troubleshoot anything else.
Shadow distance and shadow quality are third. These are the highest VRAM consumers after textures, and Ultra shadows cause large drops in dense cells. The engine default shadow map resolution is 4096; 2048 is visually near-identical and 512 is a large gain on weak hardware.
See what render scaling actually saves →Real internal pixel count at any scale percentage before you change a setting.Cap the frame rate before you upgrade anything
Fallout 4's physics is coupled to frame rate, so above roughly 60 FPS the engine misbehaves — objects launch, scripts desync, and crashes follow. Lock to 60 through your GPU control panel, or install the High FPS Physics Fix mod if you have a 120Hz or faster display and want more than 60.
- Texture quality: High on a 4GB card, Ultra at 6GB or more. Ultra textures use disproportionate VRAM and are a frequent crash cause below 4GB.
- Anti-aliasing: TAA. It is cheap and handles the game's shimmer better than the alternatives.
- Benchmark downtown Boston specifically. Indoor cells and menus hide instability that only appears in the densest worldspace.
Cut those three settings, cap your frame rate, and Boston stops being a slideshow — without stripping the Commonwealth of what makes it look like itself.
If it only broke after the next-gen update
Then the likely cause is your mod list, not your settings. That update invalidated a large number of previously stable mods, and not all of them have been patched since. Either wait for compatibility patches or downgrade to version 1.10.163, which remains the stable baseline most modding guides target. Back up your saves before you take either route.