Mathematica 7 slow under Ubuntu 10.04 (lucid)

[konstant@mail.ntua.gr]

After spending a lot of time trying to resolve how to make Mathematica 7.0 not to consume a lot of CPU resources, I decided to summarize it here, in case people find it helpful. First download the attachments. Then (assuming the tar.gz files are in your home directory ~/):

> cd /usr/local/Wolfram/Mathematica/7.0/SystemFiles/Libraries/Linux
> sudo mv libML32i3.so 00-libML32i3.so
> sudo tar xvfz ~/libML32i3_for32.so.tar.gz
> sudo chmod a+rx libML32i3.so
> cd ../Linux-x86-64/
> sudo mv libML32i3.so 00-libML32i3.so; sudo mv libML64i3.so 00-libML64i3.so
> sudo tar xvfz ~/libMLfor64.tar.gz
> sudo chmod a+rx libML*.so

Java still takes ~ 15% CPU time. Open a (separate) notebook and
Needs["JLink`"]
UninstallJava[]

Every time you use java (e.g. in the Help center), java starts again. When you finish and don't wish to spend the 15% CPU time anymore, call
UninstallJava[]
again (...and again)

Some people find it useful to disable java alltogether:
> cd /usr/local/Wolfram/Mathematica/7.0/SystemFiles/Links/
> sudo mv JLink 00-JLink
Help center is not available in that case (as well as other java stuff). Rename 00-JLink back to JLink and you are back to normal (uh, well...)

References:
http://ubuntuforums.org/showpost.php...2&postcount=46
http://ubuntuforums.org/archive/inde...t-1136142.html
http://www.linuxtent.com/?p=266
and possibly many more...



-------------------------------------------------------------

I also got the following response from Wolfram:

Hello Konstantinos,

Thank you for the email.

This is a known issue, and we advise the users who get into High CPU usage
to use the following Binary instead.

http://download.wolfram.com/?key=QNQKNV



Sincerely,

Aravind Hanasoge, Ph.D.
Technical Support
Wolfram Research, Inc.

[Garyu]

Shouldn't it be possible to just have Java on one core and do the math stuff on other cores? Most people have dual- or quad-core processors nowadays but afaik Mathematica only uses one core by default...

[adeelajaib]

Thanks Konstant

[evencoil]

The java enabling/disabling seems like kind of a pain (at least for someone like me who needs to consult mathematica help constantly).

Is the performance increase from just changing the libraries significant?

[lucasp0927]

Nice tutorial, thank you!

[matyi!dog?]

This fix worked great on my Dell xpsM1330 .
Now Mathematica 7 consumes only 2.3% CPU when not computing.
On clicking Help, Java kicks in and consumes 15% from then on.
Following the kill Java solution does remove Java until the next click on Help.

Thanks for the effort to solve the CPU problem with Math 7 on Ubuntu 10.04.
I have resisted upgrading to 10.04 until this was solved
since I use Mathematica every day for my number/plotting crunching.