1. This section of the forums is now closed. You can post and answer support requests on the new support site here

JVM Arguments for Modded Minecraft (Updated 12/30/13)

Discussion in '[Archived] Tech Support' started by Eyamaz, Aug 13, 2013.

  1. TomeWyrm

    TomeWyrm New Member

    The main thing making these java arguments require 64 bit are the "-Xms2048m -Xmx2048m" if you lower those numbers it won't require you to use more memory than a 32 bit system can hold. That's the first part of what I said.

    The next part is a warning not to do that because the entire point of these performance tweaks is to use a bunch of ram to offload some of the performance problems in modded Minecraft. Ram that you won't be able to use at all in a 32-bit system.

    And as far as I'm aware, the packs DO run just fine on 32 bit systems. The packs don't use these performance tweaks. These are special/separate/unofficial and you have to add them yourself.

    I'm sure if you go here: http://support.feed-the-beast.com/ and aska question, you should get help and could probably run Monster or DW20. If not, there are mods that can easily be removed from them to give you nearly the same experience without killing your computer. Or the FTBLite pack (they still have that, right? I haven't booted up the FTB launcher in ages. I play my own self-assembled modpack).

    Some people can't play "all the mods" at once, which just sucks; but a smaller modpack isn't all that bad. It's tough to experience all the content of something like Monster!
  2. Eyamaz

    Eyamaz New Member

    How are people still posting here? This thread is supposed to be archived and locked. @Captainnana

    But Tome is correct. The arguments in the OP have nothing to do with a 64bit requirement for packs. We recommend 64bit for the packs because there are several memory intensive mods.
  3. Derpysauce

    Derpysauce Well-Known Member

    And to think all these people who have realised FTB is a better place would have blamed the FTB team if not for mistakes

    EDIT: starting to be less exited about figures of higher magicness acknowledging my existence as it is happening a seemingly high amount
    Sorry but no flip out for ju XD
    Last edited: Mar 12, 2014
    Eyamaz likes this.
  4. keybounce

    keybounce New Member

    Step one in lowering memory usage is to change the "2048m" values to smaller ones -- try "1500m", or "2000m", or "1999m", etc.

    Step two is to locate where it is using more memory than it has to for better speed.

    (Let me take a quick look at that OP ...)
  5. keybounce

    keybounce New Member

    Well, that's pretty clear.

    Still ...
    I'd change "PermSize" to "MaxPermSize" -- let Java use as much as it needs for code, and not be unable to use more for normal usage. The "PauseMillis" I'm not familiar with (and actually, I thought those were for the G1GC collector, not the CMS collector). "BindGCTaskThreadsToCPUs" -- Can't comment, haven't used/tried.

    Potential serious danger: As soon as 60% of your memory is in use, you expect constant garbage collection. I normally put the occupancy fraction higher (it is a tunable, test on your modpack), and do not enforce the "occupancyonly" -- I let java use some smarts. If you do have constant GC, then you'll want to add in explicit max threads to use less than your number of cores so that your minecraft can operate at the same time. (Figure three cores for the server main thread, the client main thread, and some background stuff such as networking/IPC. Note that I don't know how the two halves of the single player talk to each other; the dedicated server/client do use sockets.)


    In the worst case, if you have more system ram than you can give to a single minecraft process, you may be able to run it as two processes. None of the GUI code/memory usage is needed on the server, and none of the worldgen code/memory usage is needed on the client.[/code]
  6. Eyamaz

    Eyamaz New Member

    The pauses were added to the cms code in j7u45. Hence the requirement for that version or greater.
  7. Captainnana

    Captainnana New Member

    You just can't create new threads at the moment you can still reply to existing ones for now
    Eyamaz likes this.
  8. mike546378

    mike546378 New Member

    Anyone able to let me know what args to use on a Monster server with a E5-1650 v2 Hexacore CPU, 64Gb ECC DDR3 RAM and a 240Gb 6Gb/s SSD? Get crazy amounts of lag when people are exploring new chunks, CPU core shoots upto 100%. Averaging 25-40 people online during these lag spikes. Thanks for any help. Using centOS btw
  9. Henry Link

    Henry Link Popular Member

    I too would be interested in this. The tick rate on my server drops under 6 or lower when new terrain is being generated. The server is Ubuntu 13.10 running two SSDs in hardware raid 0 config. So I know it isn't the hard drive causing this issue.
  10. TomeWyrm

    TomeWyrm New Member

    I would pre-generate terrain if I were you guys. Fly around in creative mode, use OPIS in "loaded chunks" mode (middle click on blank areas to generate them), do we have chunkloading turtles anymore if so that's a great set-and-forget method
  11. Wagon153

    Wagon153 New Member

    You can use chicken chunks and/or railcraft admin anchors.
  12. crazykilla420

    crazykilla420 New Member

  13. Wagon153

    Wagon153 New Member

  14. FyberOptic

    FyberOptic New Member

    I wanted to throw my two cents in here in case it might help someone.

    I run a 32-bit Win7 system with 4GB of ram. I have 64-bit Windows installed as well but there are various reasons I'm still primarily in 32-bit, from dev stuff as well as general laziness! I've been running Minecraft with the following JVM options recently:

    -XX:+AggressiveOpts -XX:+UseFastAccessorMethods -XX:MaxPermSize=256m -XX:+UseParNewGC -XX:+UseConcMarkSweepGC -XX:+BindGCTaskThreadsToCPUs -XX:+UseCMSInitiatingOccupancyOnly -XX:CMSInitiatingOccupancyFraction=80
    I have Java 6, 7, and 8 installed. I can tell you that Java 6 is by far the best out of all of these for running Minecraft 1.6.x packs, in my personal experience. Java 7 chokes out of memory, usually at startup, either resulting in a crash or lots of GL errors. Java 8 works, but is not quite as zippy as 6. I honestly haven't had enough time to play with 8 further since it's still pretty new, but it seems promising.

    Oddly enough, I believe Java 7 runs Minecraft 1.4.x packs better for me.

    To get the absolute best framerate, I set the performance to "balanced" in fullscreen mode with vsync enabled. Though I run in a window more often than not, in which case I disable vsync because that hurts the framerate when I'm not fullscreen.

    I've tried a lot of different things to squeeze performance out of this game for quite some time, and this is what works best for me on my specific machine. Mileage may vary.

    EDIT: Oops, I copy/pasted that JVM string from MultIMC, so it doesn't have memory settings. In the FTB launcher it has -Xmx1024m -Xms1024m as well.
  15. DarthKnight720

    DarthKnight720 New Member

    So, I downloaded the FTB.jar and for some reason I can't create a profile and use it. It just says it's invalid. Even though I made like 50 of them just to try specific number or etc. Is it just me being a noob or other things.

    Please help.
  16. Derpysauce

    Derpysauce Well-Known Member

    You need to use your minecraft account that you bought for 25$ I think is the current price tag just type in minecraft and click the first site buy it make the account then use your username and password for FTB
  17. Gr3n

    Gr3n New Member

    Thank you so much for this, not a single bit of lag after implementing these!
  18. DarthKnight720

    DarthKnight720 New Member

    So, I downloaded the FTB.jar and for some reason I can't create a profile and use it. It just says it's invalid. Even though I made like 50 of them just to try specific number or etc. Is it just me being a noob or other things.

    Please help.
  19. DarthKnight720

    DarthKnight720 New Member


    Please help.
  20. Derpysauce

    Derpysauce Well-Known Member

    Already told you you need to go buy minecraft then type in your username and password into the profile selector it's a one time payment

Share This Page