CHEAPLE'S OPTIMIZATIONS FOR BUCK

Project Zomboid668 views15 favorites4 min readby CheapleUpdated Jul 10View on Steam ↗

Quick aside

If you do plan on playing with Charborg and Criken on Build 41 again, you will have to repeat the file edit section. Luckily if you follow my steps and then make a backup of the edited file, it should be as simple as copy and pasting it into the main file once you go back to Build 42!

your flesh was delicious

If you have any questions I'll probably be in chat and be able to help.

File edits

If you don't want to use the following mod, skip this section and go to File edits without using mod.

This section revolves around the ProjectZomboid64.json file I had you edit the other night. I'll include some extra stuff that might help (these helped me personally).

If you can't remember how to get to said file go to Zomboid on steam, right click it in your library, browse local files, then find and open the ProjectZomboid64.json as a text file or whatever works.

You mentioned you had a backup file already so if you want to look that one over or create another backup in case these optimizations don't work for you then be my guest.

IMPORTANT: If you are doing this, this section's optimizations require a mod that you must add:
https://steamcommunity.com/sharedfiles/filedetails/?id=3459875383
Make sure to add it to your mod list and the server you use (also add it to your chaos mod preset)

NOW THEN
With this file open, copy and paste the everything below this into there, this includes everything that should be in the entire text file so just copy and paste over everything that's in there already.

{ "mainClass": "zombie/gameStates/MainScreenState", "classpath": [".", "projectzomboid.jar"], "vmArgs": [ "-Djava.awt.headless=true", "-Xms6g", "-Xmx12g", "-XX:+UseParallelGC", "-XX:ParallelGCThreads=4", "-XX:+UseNUMA", "-XX:+AlwaysPreTouch", "-XX:+DisableExplicitGC", "-XX:+ParallelRefProcEnabled", "-XX:+OptimizeStringConcat", "-XX:+UseStringDeduplication", "-XX:+UseCompressedOops", "-Dzomboid.steam=1", "-Dzomboid.znetlog=1", "-Djava.library.path=win64/;.", "-XX:-CreateCoredumpOnCrash", "-XX:-OmitStackTraceInFastThrow" ], "windows": { "6.1": { "vmArgs": [ "-XX:+UseParallelGC", "-XX:G1NewSizePercent=20", "-XX:G1ReservePercent=20", "-XX:MaxGCPauseMillis=50" ] }, "10.0.17134": { "vmArgs": [ "-XX:+UseParallelGC", "-XX:ConcGCThreads=2", "-XX:+UnlockExperimentalVMOptions" ] } } }

If you did everything correctly it should look like this:

Remember to save the file!

Copy the whole thing and replace everything in that ProjectZomboid64.json, make a backup of the original incase you decide to undo this.

IMPORTANT: I'm assuming you have 32gb of RAM on your pc but incase you only have 16gb of RAM, go ahead and replace the -Xms and -Xmx commands with these:
-Xms4g
-Xmx8g
These will give Zomboid less ram (but still more than default) so your other applications like OBS can still run well, feel free to tinker with giving more or less as needed.

It's also wise to keep a seperate copy of your config file exactly the way it is now, so if these changes somehow affect the chaos mod or your game negatively you can go back to how it way before (just make sure the RAM is still set to more than 3gb as increasing that above the game default value shouldn't cause any conflicts).

Helpful mods

Some other mods that help that I use, make sure to add them to your preset and the save you plan on using:

https://steamcommunity.com/sharedfiles/filedetails/?id=3119788162
You can choose between optimal or performance mode for textures in the main menu, honestly just set it to optimal, performance is for potato PCs and I doubt your GPU is where the bottleneck is happening.

https://steamcommunity.com/sharedfiles/filedetails/?id=3423660713
The default project Zomboid mod load order just sorts your mods alphabetically when choosing auto which can actually break some mods, this one should set this in the correct order automatically 99% of the time. Not needed but I would recommend.

My performance using these methods

Here's a comparison in a location I'm sure you remember well. Standing in the heart of Louisville with a very large number of zombies loaded I'm getting around 60-100 fps as you can see in the bottom left. My PC is very good so I'm sure mileage may vary but hopefully after following my guide you too see a noticeable jump in performance that will make all future streams more enjoyable and lead to fewer deaths!

My specs for comparison:
GPU: Rtx 4070
CPU: i7-13700KF
Ram: 32gb DDR5
Hard drive: SSD ----> (Using an SSD over an HDD is recommended for any game since it improves load times and increases FPS when new assets are loaded midgame)

File edits without using mod

Skip this section if you decided to use the mod and file edits from first part.

If you don't want to use the Multicpu mod and/or forgot to make a backup of your original files before completing part 1, here they are.

The initial code you had with RAM edits:

{ "mainClass": "zombie/gameStates/MainScreenState", "classpath": [ ".", "projectzomboid.jar" ], "vmArgs": [ "-Djava.awt.headless=true", "-Xms6g", "-Xmx12g", "-Dzomboid.steam=1", "-Dzomboid.znetlog=1", "-Djava.library.path=win64/;.", "-XX:-CreateCoredumpOnCrash", "-XX:-OmitStackTraceInFastThrow" ], "windows": { "6.1": { "vmArgs": [ "-XX:+UseG1GC" ] }, "10.0.17134": { "vmArgs": [ "-XX:+UseZGC" ] } } }

It should look like this if done correctly: