Hey fellow modding community, in the last few days I came across an issue that might concern a lot of people. I´m talking about sudden stutters and "lagspikes". TL;DR: Theory: Editing NPC templates/records with FO4Edit may cause the game to stutter, when edited NPC´s get loaded. Small disclaimer: I know how much work needs to be done to create and maintain a mod and my deepest respect goes to all mod authors who work in their sparetime to give us all the great mods we have for free. This post should not be considererd as a demand to the authors or an insult. It´s just something I wanted to share with you all, because I´m not sure if mod authors are aware of this issue. And maybe there is a solution that helps to improve stability and performance for all of us, be it author or user. The problem part 1: I just sterted a new (obviously modded) game and everything went fine, until I had to meet Preston in Concord. After passing red rocket station I got a serious stutter. Meaning my Framerate went from solid 58-60 down to 0-3 for a few seconds. I was able to recreate the stutter by loading a previous save, and everytime i passed red rocket my game stuttered. Investigation part 1: So, I started investigating. I disabled all mods and loaded the save. The result was super-smooth, no stutter at all. then I activated the first 5 mods, loaded the game, no stutter, then the next 5 mods, reloaded, and so on. FiInally I figured out that the Raider Overhaul was causing the stutter, I deactiveted it, enabled all other mods and again no stutter. After a little bit of research I read, that the issue is known to the mod author and he´s working on it (same goes for his really amazing super mutant overhaul) The problem part 2: After playing a few hours with my now "smooth-again" game, I came across the next big stutters. Everytime I approached the drumlin diner and Trudy, Wolfgang and Simone got "loaded" into the cell. I´m using the "Immersive Drumlin Diner" mod and my guess is, its the same issue (but I can´t confirm it for now) The same is true if I walk back to Sanctuary. The stutters always occure at the same spot in the world and are "re-creatable". ("Better Settlers" is in my loadorder) Investigation part 2: This morning I googled if someone else got the same Problem and I might found something that could be interesting for everyone altering NPC´s in the FO4 world. The (possible) root of the problem: http://3dnpc.com/question/fallout-4-stutters-npctemplate-related-3/ Basicly it looks like an engine problem with some NPC records/templates that are locked in the CK, but you can edit them in FO4Edit. Unfortunately they brake and cause the game to stutter everytime a edited NPC gets loaded into a cell. Which, I´m guessing in my case, happens with "Better Settlers" and "Immersive Drumlin Diner". Things I tried without success: - Run FO4 on high CPU prio (made it even worse) - Fiddled around with adaptive VSync - Changed/lowered Graphic-settings - Removed Texture-mods - Fiddled around with the ENB Boost settings Things to test on my list: - Switching to fullscreen //EDIT: slight decrease of the stutter - Disabling Shadowboost //EDIT: no change - Disable "Immersive Drumlin Diner" (see if it fixes the stutter in this specific cell) //EDIT: Stutter removed - Disable "Better Settlers" (see if it fixes the stutter in this specific cell) //EDIT: Stutter removed Maybe important: All the stutters happen with a CPU usage of 80% and GPU/VRAM usage of ~ 65-75%. During the stutter my CPU usage drops to ~25% and GPU/VRAM to ~20% --- Please remember, that all the things I described are my observations, experiences and research. I just wanted to share it with you, hoping that there is a solution. But maybe I´m completely wrong and the whole problem is my own fault :D FYI my Specs: Intel i5 4x 3.3 GHz Zotac GTX 980 Ti Amp! extreme 6GB 16 GB RAM I´m running Fallout 4 on Ultra (3440x1440, 21:9) via MO2, F4SE, Shadowboost and ENB Boost in borderless windowed mode. //EDIT: My loadorder: //EDIT: Well, after disabling "Immersive Drumlin Diner" and "Better Settlers" (All related esp´s) the stutter was gone in both areas and I was back to my regular 58-60 fps all the time. I tried it several times, approached the cell from different directions and different time of day/night. I hope someone finds this information useful, even if its just to be aware of it, before altering NPC´s. Greetings Still P.S. Sorry for my (probably) bad english. //EDIT: Sorry, I just realized, that I posted this thread in the wrong forum. It should probably be in the technical support. My apologies :-/