There have been multiple accounts created with the sole purpose of posting advertisement posts or replies containing unsolicited advertising.

Accounts which solely post advertisements, or persistently post them may be terminated.

Java uses double ram.

Let’s be honest: I only use Java for Minecraft. So I only debugged with it. But all version, server or client, all launchers. All of them use double (or more) RAM. In the game the correctly allocated amount is used, but on my system double or more is allocated. Thus my other apps don’t get enough memory, causing crashes, while the game is suffering as well.

I’m not wise enough to know what logs or versions or whatever I should post here as a cry for help, but I’ll update this with anything that’ll help, just tell me. I have no idea how to approach the problem. One idea I have is to run a non-Minecraft java application, but who has( or knows about) one of those?

I’m on arch (btw) (sry)

ScottE ,

This is normal behavior. There is much more to the JVMs memory usage beyond what’s allocated to the heap - there are other memory regions as well. There are additional tuning options for them, but it’s a complicated subject and if you aren’t actually encountering out of memory issues you have to ask if this is worth the effort to tune it.

possiblylinux127 ,

Minetest.net

Lemmchen ,
@Lemmchen@feddit.org avatar

stackoverflow.com/…/how-to-set-the-maximum-memory…

taaz , (edited )

As a side note and a little psa, if you need to squeeze out more overall performance of out of MC (and you are playing vanilla or Fabric modpack) I very much recommend using these Fabric mods: Sodium, Lithium, FerriteCore and optionally Krypton (server-only), LazyDFU, Entity Culling, ImmediatelyFast.

UnRelatedBurner OP ,

haha, thanks! But I already knew about most of them :D

taaz ,

You could also (hard) limit the total (virtual) memory process will use (but the system will hard kill it if tries to get more) with this:
systemd-run --user --scope -p MemoryMax=8G -p MemorySwapMax=0 prismlauncher

You would have to experiment with how much Gs you want to specify as max so that it does not get outright killed. If you remove MemorySwapMax the system will not kill the process but will start aggressively swapping the processes’ memory, so if you do have a swap it will work (an depending on how slow the disk of the swap is, start lagging).

In my case I have a small swap partition on an m2 disk (which might not be recommended?) so I didn’t notice any lagging or stutters once it overflow the max memory.
So in theory, if you are memory starved and have swap on a fast disk, you could instead use MemoryHigh flag to create a limit from where systemd will start the swapping without any of the OOM killing (or use both, Max has to be higher then High obv).

UnRelatedBurner OP ,

terminating if X is a very bad idea. I wouldn’t fancy loosing progress and corrupting my world

boredsquirrel ,
@boredsquirrel@slrpnk.net avatar

I only know Optifine. What is fabric?

taaz ,

Fabric is one of many mod loaders ala Forge. It’s newer and less bulky then Forge (but afaik it already did have it’s own drama so now we also have a fork called Quilt, the same goes for Forge and NeoForge).

The mods I’ve specified above can be considered as a suite replacement for the (old) OptiFine.

E: For example this all the mod loaders modrinth (mod hosting website, curseforge alternative) currently lists:

https://biglemmowski.win/pictrs/image/9191dc35-8ac5-46e2-974c-0ecb5eeef741.webp

LazaroFilm ,
@LazaroFilm@lemmy.world avatar

Let j for the modpack AdditiveIt’s based on Fabric with some great mods oriented towards speed and QOL which replace OptiFine in one package.

jrgd ,

Depending on version and if modded with content mods, you can easily expect Minecraft to utilize a significant portion memory more than what you give for its heap. Java processes have a statically / dynamically (with bounds) allocated heap from system memory as well as memory used in the stack of the process. Additionally Minecraft might show using more memory in some process monitors due to any external shared libraries being utilized by the application.

My recommendation: don’t allocate more memory to the game than you need to run it without noticeable stutters from garbage collection. If you are running modded Minecraft, one or more mods might be causing stack-related memory leaks (or just being large and complex enough to genuinely require large amounts of memory. We might be able to get a better picture if you shared your launch arguments, game version, total system memory, memory used by the game in the process monitor you are using (and modlist if applicable).

In general, it’s also a good idea to setup and enable ZRAM and disable Swap if in use.

taaz , (edited )

Big modpacks that add a lot of different blocks will also always explode the memory usage as at the start, Minecraft pre-bakes all the 3d models of the blocks.

UnRelatedBurner OP , (edited )

launch arguments [-Xms512m, -Xmx1096m, -Duser.language=en] (it’s this little, so that the difference shows clearly. I have a modpack that I give 8gb to and uses way more as well. iirc around 12)

game version 1.18.2

total system memory 32gb

memory used by the game https://i.imgur.com/loRZxqu.pngI’m using KDE’s default system monitor, but here’s Btop as well: https://i.imgur.com/JP3I9MX.png

also: this test was on max render distance, with 1gb of ram, it crashed ofc, but it crashed at almost 4gbs, what the hell! That’s 4 times as much

jrgd ,

For clarification, this is Vanilla, a performance mod Fabric pack, a Fabric content modpack, Forge modpack, etc. That you are launching. If it’s the modpack that you describe needing 8gb of heap memory allocated, I wouldn’t be surprised the java stack memory taking ~2.7 GiB. If it’s plain vanilla, that memory usage does seem excessive.

UnRelatedBurner OP ,

This was Vanilla.

jrgd ,

Running the same memory constraints on a 1.18 vanilla instance, most of the stack memory allocation largrly comes from ramping the render distance from 12 chunks to 32 chunks. The game only uses ~0.7 GiB memory non-heap at a sane render distance in vanilla whereas ~2.0 GiB at 32 chunks. I did forget the the render distance no longer caps out in vanilla at 16 chunks. Far render distances like 32 chunks will naturally balloon the stack memory size.

Max_P , (edited )
@Max_P@lemmy.max-p.me avatar

When you control the memory allocation for Minecraft, you really only are configuring the JVM’s garbage collector to use that much memory. That doesn’t include any shared resources outside of the JVM, such as Java itself, OpenGL resources and everywhere else that involves native code and system libraries and drivers.

If you have an integrated GPU, all the textures that normally gets sent to a GPU may also live on your regular RAM too since those use unified memory. That can inflate the amount of memory Java appears to use.

A browser for example, might not have a whole lot of JavaScript memory used, couple MBs maybe. But the tab itself uses a ton more because of the renderer and assets and CSS effects.

UnRelatedBurner OP ,

This is interesting and infuriating, but I don’t think this is quite right in my scenario. As I also observe the over-usage when running a server from console. There shouldn’t be any GPU shenanigans with that, I hope.

  • All
  • Subscribed
  • Moderated
  • Favorites
  • •
  • [email protected]
  • random
  • lifeLocal
  • goranko
  • All magazines
    •