Simulation distance refers to the distance, indicated by the number of chunks, around the player that the game engine will load entities and update them. All blocks and items inside a player’s simulation distance will function normally, while everything else outside of this area is suspended and inactive.
This is often talked about together with render distance, which is a similar metric but instead only refers to the distance around the player that the game will load entities and show them to the player, without applying any changes to them.
Why Simulation Distance Matters
Minecraft normally runs at 20 game ticks per second, so that means that the game updates the states of the various entities in the game 20 times per seconds. Simulation distance refers to the number of chunks around the player that are going to be loaded and updated every game tick.
Automatic farms like these will not work if they go past your simulation distance
A good example of simulation distance in action is when you are making an automatic farm. You will notice that going far enough would stop your farm’s production. This means that your farm is now past your simulation distance, and the game has unloaded them. Hence, your farm has effectively stopped working.
Redstone circuits also don’t work if you’re far enough from them
Redstone contraptions are also subject to simulation distance. If they are outside of your simulation distance, redstone circuits will not work, especially if they span very large distances.
Simulation distance also affects entities of the game that can move or grow away from a point. Mobs will not spawn outside of the simulation distance, and if they move away from the simulation distance, they will become motionless but still visible. This is true for most entities like flowing water and grass.
Basically, the game does not do anything to entities that are outside of a player’s simulation distance. A high simulation distance might be better in theory, as it allows a larger area around you to be interactive. However, it would consequently require a high processing load on the device. If set too high, the game might become too slow, since the game is attempting to process too many chunks all at the same time. Properly setting your simulation distance is key in being able to play Minecraft with the best experience.
Simulation Distance and other Similar Terms
Large render distances do not mean that everything you see are operational
Simulation distance is different from render distance. Render distance is primarily concerned with being able to display parts of the world that are near the player, and is often higher than simulation distance. Because of the difference between simulation distance and render distance, not everything you see might be actually operating or updating. You might be able to see your crops from afar, but if they are outside of your simulation distance, then they are not actually growing, despite the fact that you could see them.
Another term that is similar to simulation distance is a ticking area. A ticking area is an area in the world that is constantly loaded, which means that it is always updated. However, a ticking area does not have to be near the player, and it has to be explicitly defined via commands. Simulation distance can be thought of as a natural ticking area around the player.
Setting your Simulation Distance
You can only change the simulation distance if you’re not in the world, so you will need to exit from the world if you’re already there. You can find the simulation distance setting in the game settings from the world selection screen.
Set your simulation distance setting before you enter a world
Go to the Games tab, and right under the Seed textbox, you can see a slider for simulation distance. The default value is 4 chunks, which is equal to 64 blocks at all cardinal directions. The maximum simulation distance is variable, as it changes depending on how the game evaluates the performance of your machine.
It should be noted that for the current version of the game, Minecraft: Caves and Cliffs Part I, simulation distance is a setting only present in the Bedrock Edition. As the Bedrock Edition caters to more platforms than the Java Edition, it makes sense for the game to be able to adjust the load according to the device it is on. However, for the next update, Caves and Cliffs Part II, the setting for simulation distance will also be available in the Java Edition.
If you find your game getting a bit too laggy for your liking, you might want to check on your simulation distance settings. If you have no urgent need to simulate a part of the map that might be constantly far away from you, then you might want to drop your simulation distance to the default.
Of course, the same could be said for the opposite. If you are confident that your machine can handle a higher simulation distance, and if you do need to keep a part of the map active at all times, then you can try upping the simulation distance for a better experience.