Arch Linux

surfhai

Member

Registered: 2010-06-26

Posts: 6

cpu clock speed is set to minimum while playing minecraft

my cpu is able to run from 800MHz up to 2,5GHz (laptop) running archlinux with oracle jre. If I play minecraft my cpu clock speed is always set to 800MHz. I have stopped the daemon cpufreq and the laptop-mode isn't touching the cpu clock speed anymore. I can't play minecraft at 800MHz. If I stop playing minecraft and exit my clock speed is back to normal after some seconds.

cpufreq-info (sorry the output is german) http://pastie.org/1682080
java version "1.6.0_24"
Java(TM) SE Runtime Environment (build 1.6.0_24-b07)
Java HotSpot(TM) 64-Bit Server VM (build 19.1-b02, mixed mode)

here a video http://www.megaupload.com/?d=GEG412I0

    $ strace `java -Xmx1024M -Xms512M -jar minecraft.jar`
    java.io.IOException: mark/reset not supported
            at java.io.InputStream.reset(InputStream.java:334)
            at java.io.FilterInputStream.reset(FilterInputStream.java:200)
            at hz.b(SourceFile:123)
            at lt.c(SourceFile:155)
            at lt.c(SourceFile:9)
            at sj.run(SourceFile:62)
    AL lib: alBuffer.c:1081: exit(): deleting 3 Buffer(s)
    strace: 28: command not found

I have started the same thread here in the minecraft forum, but they don't know how to solve it
http://www.minecraftforum.net/viewtopic … 3#p3270073

Edit: ok, I think it is a general problem on my machine with java. At the moment the only java program that is running is the jdownloader and my computer shows the same behavior as with minecraft. cpu clock speed at only 800MHz

I've restartet /etc/rc.d/cpufreq and it runs nice with jdownloader again, but if I start minecraft it is at 800MHz.

Last edited by surfhai (2011-03-17 14:52:29)

stqn

Member

Registered: 2010-03-19

Posts: 1,191

Website

Re: cpu clock speed is set to minimum while playing minecraft

You can use "LANG=C cpufreq-info" to output the info in English.

From what I've seen it looks like /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq is set to 800 when minecraft is running... Either java is doing something weird, or this is laptop-mode-tools? I'm not using the cpufreq daemon nor laptop-mode-tools but I think the daemon is only used to set scaling values at startup so it shouldn't cause this problem.

Or maybe your CPU is overheating?

R00KIE

Forum Fellow

From: Between a computer and a chair

Registered: 2008-09-14

Posts: 4,734

Re: cpu clock speed is set to minimum while playing minecraft

As a workaround set the cpu governor to performance before playing and restore it to ondemand after exiting the game.

On the other hand for you to have your cpu running at 2.5GHz with the ondemand governor _before_ entering the game then you must have something eating cpu cycles or something is wrong there.

---

R00KIE
Tm90aGluZyB0byBzZWUgaGVyZSwgbW92ZSBhbG9uZy4K

thestinger

Package Maintainer (PM)

From: Toronto, Canada

Registered: 2010-01-23

Posts: 478

Re: cpu clock speed is set to minimum while playing minecraft

all the daemon does is set the governor, it isn't actually a program that keeps running (just like the alsa "daemon")

this is probably what you need:
https://wiki.archlinux.org/index.php/Cp … _threshold