Fallout 4

About this mod

Previsibines performance upgrade package for Fallout 4, covering the entire game. Depending on location, could give from 2 FPS to 30+ FPS increase, also includes any relevant bug fixes I can find and fix not already covered by UF4OP. Requires Season Pass / All main DLC.

Permissions and credits

aka: The Unofficial Fallout 4 Precombines Patch

[ PRP-Main | PRP-SS2 | PRP-Vault120 ]

Looking for a capable xEdit script crafting expert to deal with a long standing problem in generation. If interested, please check in on our discord.

If you are here following the BitRaitRec guide PDF, you want the latest Stable release as listed below, instead of what the document tells you, as PRP no longer has split packages. (Historically before 0.49, PRP came in Ext and Int packs.)

This mod assumes your DLC .esm files are pristine and uncleaned. Fear not, the main side of the work in cleaning them (the UDRs) are included in PPF.esm. Though cleaning them from what I've heard might have unexpected effects based on certain community hearsay, I'm not your mother. Make your own decision on that one.

Stable was built against UF4OP 2.1.3 up to 0.59, 0.60 and newer builds built against UF4OP 2.1.4. Previous users can safely update, as long as they are on 0.59.7 or newer.

The bolded marked version in the list just below this line is the recommended version to download, and any and all patches should expect it. If you create patches against PRP, it's a good idea to keep an eye on the discord's support channel. Usually version bumps are announced in advance.

Current mod Stable releases: 0.59
Current mod Unstable release: 0.60

Current direct contributors:
krrptd, Glitchfinder, VlitS, feeddanoob, VishVadeva50, CyberDanz, ... [if you've contributed here and want named, please let me know, I'm going off memory here]

Included mods with first versions implemented:
Collision Fixes from Scrap Everything (0.55), Flicker Fixer (0.57, minus a pair of posters intended to fix an issue with vanilla precombines that we don't need), Airport Transparency Fix (0.58), Far Harbor - Cliffs Edge Hotel Wall Rest Ring Lower Fixed (0.58), Cliff's Edge Hotel Window Fix (0.58), Glitch's Fixes (0.58), Vault 111 Floor Guide Fix (0.58), Technically any mod that adds Max Height records to Nuka World, but we freshly generate it. (0.57), Collision and Mesh updates from Exoclyps as part of the Storywealth Collective patch (0.60)

Current Translator credits:
Spanish (Spain): kittyowilder, Italian: samyesu, Brazilian Portuguese: Rikintosh2, French: Whoever maintains the UF4OP French translation (to be filled in), Japanese: Anonymous users from 2game, Polish: [to be filled in], Simplified Chinese: Vozhuo

Constantly updated changelog/bugtracker: Here.
Primary Support Discord (Collective Modding): Here.

Please see the sticky post in comments for more recent information than what's below, and pardon the dust.


PRP started out as an attempt to replace the aging and technically broken (the user base patched around it's flaws) Fo4FI_FPS_Fix which it itself was a replacement of Boston FPS Fix, both mods originally attempts to update the information provided to the precombine and previsual system in first the general Boston area (thus the name), and then the entire Commonwealth (the other mod) to improve performance and restore it in some cases where it was previously broken through official patches. For my mod, I historically did it all cell by cell in the Creation Kit the old fashioned way, up till 0.49 was created when several fine people were already figuring out the internals of the Creation Kit and how to set up the hidden command line mode of generation for the system itself. I did some independent testing at first and eventually caught wind of several discord servers that have given me countless advice and assistance in construction of the mod itself. This mod would not have been what it is today without the help of the community.

Special shout outs to ShadowOfTheWind (setting me straight at the beginning regarding visibility generation), VlitS, Searge, Evan, yarrmateys (Various assists and improvements via tools and technical assistance with issues that had came up in the mod's development), CyberDanz, ScreamingLake, Marvesly, MasterLix, and various others in the support discords for so much help and support with QA, feeddanoob, Hap, Poet, krrptd for compat patch development or in the case of Frost, replacement and additional contributed bugfixes. Arthmoor for the obscure history lesson pulled from their bug tracker and the rare piece of advice. Also countless others that have reported bugs and helped out with user support issues that for the life of me, I cannot fit in the mod description.

Though the mod does technically depreciate both of the above mods, I never intended to obsolete BostonFPSFix, as it does have a use in cases where you don't want to have so much of a compatibility window compared to mine. The original mod author is more than welcome to take the accumulated bugfixes and rebuild their mod with them in mind if they apply when they return to active modding.

Ever since 0.51 hit, I've take it upon myself to more or less try and fix what I can in the purview of what the mod touches, and as a result became an extension of the UF4OP itself by virtue of what I do, even submitting bugs myself to their tracker when it's something that either they can fix or I've already fixed and is under their purview. The entire list of changes pending and current lives at this page of the git repository I use for mod development: PRP-Bugtracker. For submitting bugs, I prefer posts with detailed information about the problem or being notified in multiple modding discords that most of the user base are likely already inside of. The primary one is at the Collective Modding discord, though I do frequent the Black Pearl, MOFAM, xEdit, Frost, Horizon, The Midnight Ride, among other obscure discords. If you frequent a certain lesser known but still used imageboard, use the Previsibines term when talking about bugs so I can search for it in the post archives easier.


PRP at it's core is an entire rebuild of the game's previsibines file set. (VlitS coined the term, it's a portmanteau of Precombines and Previsual or Umbra information.) As the mod is built against UF4OP, it absolutely requires all six mainline pieces of DLC (everything in the Season Pass except for the HD Resolution pack, which most people don't install anyway for various reasons, and I'm not giving you another one.), and thus will not change. If this bothers you, wait for a steam sale or check other places for a steam key. The information is built against the latest steam release in an automated fashion, and thus will likely never be bug free. For most people, you download the current stable release, the expected version is below the logo at the start of the description. Install that like any other mod, as it's self contained, preferably through Mod Organizer 2, but Vortex users have reported success and LOOT does recognize all mods posted on this page.

Due to the nature of the files included, there will always be issues, most of which culminate in a pair of know types of problems that are usually solved by fixing your load order.

Since 0.57, the mod includes a FOMOD and enough compatibility to be manually installed with the Wyre Bash Installers tab if the fomod converter isn't sufficient to deal with it. For most people, PPF+PRP by itself is fine, but if you have any of a small set of mods, patches are included for compatibility. LOOT's masterlist is aware of PRP's plugin set and will get your load order with respect to the mod sorted out. Don't trust it completely for every load order, though.


The CRP PRP Refurbish package, and the Delta Update packages are xdelta3 based binary update packs for the Commonwealth Reclamation Project (original version, Overgrowth has some teething issues, we're both aware of it) and for upgrading between stable revisions of PRP to avoid having people from downloading entire 1.5GB packages over again for relatively minor changes.

Common Questions and Answers

Check the pinned in the mod's comments first before reading this, as it's usually up to date with what's going on.

Q: I use FROST, do I need PRP?
A: Negative. krrptd and the Frost community maintain an equivalent to PRP that includes some of my fixes (it would be all of them, but the dev has a family to take care of, and I can understand mod dev time being limited.), which can be found here, recently remade as an all in one package in the same style as PRP! If you have questions, peruse their support discord or mod pages.

Q: I use Horizon, I've heard something about incompatibility?
A: Only with Enhanced Settlements, it's a known issue, hopefully to be resolved in 1.9. The CK crashes due to missing models. A compat patch is in the works for 1.8, but it'll have settlement cells with previs disabled. This is intended due to the way mod functionality is implemented, and the amount of time required to fix it would be not worth it, as 1.9 will have released by that point.

Q: The mod I want patched isn't available on your mod page.
A: I'm aware of four others currently maintaining compatibility patches, with another currently only supporting an older PRP build. I can only personally vouch for Feeddanoob's UPPC (as of this update only compatible with 0.53, known issue), TheSoundofSnow (Poet)'s OPC, and Hap's work.
Mith077's recent works are solid but you should still notify them of any bugs you find. Anyone else making compatibility patches should target the current stable version for best results.

Q: You mentioned CRP. Is it compatible?
A: CRP and Desperados Overhaul come with their own precombines, though they are older in style. They aren't compatible with the exception of CRP 4.2 as noted above, and I'm planning to patch Desperados properly.

Q: Any other mods you know that are compatible?
A: Pfff, I wish. Generally you'll know if the description mentions PRP or Previsibines (or Previs Repair if older) in the description. I do have a laundry list of patches that need to be made, but it's better if more people do so, you know so I can continue development!

Q: This git repository you mention, does it have documentation on how you are accomplishing this voodoo that you do?
A: Right here. Pull requests welcome.

Q: Any advice on texture compatibility?
A: Okay, a bit of a technical knowledge drop here about previsibines. They come in two formats. One is a .uvd, which is a umbra tome, the format typically used in visibility calculation and occlusion by the game for most places. The other is a .nif, as precombines are precombined meshes, or rather smashed up meshes to reduce draw calls and increase FPS in the game as a result so the graphics card doesn't have to work as hard. Since all this mod does is update or replace meshes, textures are unaffected at all. I personally use Luxor's HD texture pack in my testing.

Q: Arthmoor is icky or I hate the UF4OP team for some reason that's stupid. Make a version without it!
A: Ahahahahahahahahahahahahahaha. Ahahaha. No. The only way I will ever do that if there's a better replacement down the line.

Q: Can I ESL the mod?
A: Under the presumption I remember to keep the new record count below the requirement, you should be able to safely flag it for I think all of the mods on this page. PRP releases 0.54 or newer should have it flagged already. It's a regression or I forgot if it's not and should be reported.

Q: Geez, this question list is getting kind of long. Uhhhh, what is a man?
A: Semi-random youtube link to be funny. I don't own that video.

Q: Wait, hold up, the tutorial videos from Trosski and RedRocketTV don't match the information in the command line manual. What do I need to do?
A: Follow their guides for the GUI, except skip the first visibility generation (only do Precombined Visibility).

Q: Clean? Filtered?
A: Explained in the manual. Short version: Filtered is Creation Kit GUI (full size) and Clean is DLC and Base Game style (shared geometry which makes them much smaller, it's what PRP uses.)

Q: Console version?
A: Unless I somehow magically reduce the archive size considerably (It's 4.3GB on average), no way.

Q: There's been posts in the SS2 Forums about incompatibility with PRP. Is this true?
A: As of 2.0.1, at least as far as I'm aware, the two mods do not touch each other's records without the dedicated PRP-SS2 patch which only rebuilds certain interiors in the mod to be in the same style as PRP itself and does not touch the exteriors at all for conflict reasons. If anything would conflict WITH that patch, only missed UF4OP forwards and a specific cell header to push missing precombine headers forward.

Q: You have Delta updates on your mod page, what are those for?
A: Those are xdelta3 based file update packages designed to be used if you have previous supported versions of the mod to save on bandwidth and download times. Unpack the archive to your mod folder in MO2 or Vortex, make sure you have the executable present as I don't package it with the update packs if it's not already present in your system's path and run modupdater.bat.

Q: I use Fallout 4 VR, is PRP compatible with it?
A: Well, yes, but technically no. Either use a mod that makes the engine ignore the plugin version or manually change the plugin version for both plugin files to 0.95, or else the older game engine will refuse to load it properly. This is a known issue with the VR version, and I will not issue separate plugins to accommodate. The VR version of the game also doesn't support the ESL or light flag in plugins, you might or might not have to remove it before using it in VR. Due to differences in data files compared to the Flat game, you have to do some steps to get it to work right. Consult more VR focused reddits or modlists to get help, I can't assist due to not having the equipment required.
8/4/22 update: Apparently the current PRP version crashes VR? Needs more info. Users should strip the ESL flag from both plugins before use.

Q: I don't see a mod that has a compat patch or a bigger patch, can I do this myself and help out?
A: Read the manual, get the Creation Kit, join the discord, ask around. I'd be more than willing to help people learn how to do this so I don't have to build the patches myself and can actually do mod work!

Q: I have Creation Club content, does PRP support it in any way?
A: Pfff, no. I'm not made of money. If you want specific CC content supported by PRP, one would have to donate a specified amount of CC currency so I can pay for it, and that can be arranged in private. I will not resort to piracy for this, as the pirated content may not be pristine.

Q: What happened to the patch for Aloot's Home Plate?
A: The current caretaker has included my patch for the english version. The translated versions will eventually make their way over there in time.