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A Ruby interface for getting CPU information
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A Ruby interface for getting cpu information.


gem install sys-cpu

Adding the trusted cert

gem cert --add <(curl -Ls



Currently there is no processors iterative method for multi-cpu systems. I plan to add it this in a future release.


The CPU.model method returns very limited information. I do not yet know how to get more detailed information.


This is pure Ruby. This version reads information out of /proc/cpuinfo and /proc/loadavg, so if /proc isn't mounted it won't work.

The key-value information in /proc/cpuinfo is stored internally (i.e. in memory) as an array of hashes when you first require this package. This overhead is exceptionally minimal, given that your average cpuinfo file contains less than 1k of text (and I don't store whitespace or newlines).

The text documentation for Linux is dynamically generated during the build process because the fields vary depending on your setup. So, don't look at it until after you've installed it. You will see a doc/linux.txt file after you run +rake install+ (via install.rb).


Unlike other platforms, you can get load averages for an individual cpu in multi-cpu systems. See documentation for more details.

Note that version 0.7.x and later will not work on HP-UX because of the switch to FFI and the lack of a testing platform. However, version 0.6.x will work just fine.

MS Windows

This is a pure Ruby implementation using the win32ole package + WMI. The C version has been scrapped.

As of version 0.5.0, the CPU.usage method has been removed in favor of the CPU.load_avg method. This does not (currently) use a perf counter, so there is no longer any delay. Also, the processors method has been added and the supported method has been dropped. See the documentation for other changes.


Thanks go to the MPlayer team for some source code that helped me on certain versions of FreeBSD in the original C version.

Known Bugs

None that I'm aware of. Please report bugs on the project page at:

Future Plans

  • Add iterative CPU.processors method.

  • Add more information in general, such as what prtdiag shows.




(C) 2003-2020 Daniel J. Berger, All Rights Reserved


This package is provided “as is” and without any express or implied warranties, including, without limitation, the implied warranties of merchantability and fitness for a particular purpose.


Daniel J. Berger

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