Supposed Ubuntu Speedups - Concurrency=shell, readahead profile

Wednesday, December 31, 2008

After seeing Lifehacker blog about a number of Ubuntu speedups, I decided to test some of them to see their actual effectiveness.

The test machine was a Lenovo T61 with a Core 2 Duo T7500 @ 2.2 ghz and 3GB RAM. All boot times are from the grub menu (started when I pressed enter to start the boot) to the appearance of the login screen. I started with a completely fresh installation of Ubuntu 8.10 which I updated and rebooted 3 times. The default settings are "concurrency=none" in /etc/init.d/rc, but I'm unsure of the default readahead settings. It's possible Ubuntu tries to create a profile after installation, but I have no proof of that, so I assume there is no profile.

The results:

  • No modifications (concurrency=none, no readahead profile) - 29.8 sec
  • Concurrency=shell, no readahead profile - 29.2 sec
  • Concurrency=shell, readahead profile - 28.7 sec
  • Concurrency=none, rebuilt readahead profile - 29.2 sec
Also keep in mind all timings are subject to human error. My conclusion is that there are no notable improvements from implementing these tweaks, even with a dual core processor.

Here is my full action log:
  • Install 8.10
  • Update
  • Restart x 2
  • Restart, timed boot - 30.0 sec
  • Restart, timed boot - 29.6 sec
  • Set concurrency=shell in /etc/init.d/rc
  • Restart, timed boot - 29.9 sec
  • Restart, timed boot - 29.1 sec
  • Restart, added "profile" to end of grub line
  • Timed boot for profile creation - 1 min, 27.7 sec (This is normal)
  • Restart, timed boot - 28.7 sec
  • Restart, timed boot - 27.9 sec
  • Restart, timed boot - 29.6 sec
  • Set concurrency=none in /etc/init.d/rc
  • Restart, added "profile" to end of grub line
  • Timed boot for profile creation - 1 min, 29.1 sec (This is normal)
  • Restart, timed boot - 29.3 sec
  • Restart, timed boot - 29.1 sec

Posted by Craig Younkins at 12:07 PM  


Your methodology leaves a lot to be desired matey!

Try installing Bootchart (sudo apt-get install bootchart) to get a nice consistent measurement of what you want here for a start, then perhaps consider that the 1.1 second improvement is roughly a 3.7%, which isn't TOO shabby.

That being said, yes there are a lot of faster ways to speed up the boot out there (check out

smidgey said...
February 2, 2009 at 5:10 AM  

Buy 4 PC-21C color cartridges and get the 5th one FREE. The PC-21C color ink tank replaces the Canon BCI-21C color ink tank.
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buddypress said...
November 17, 2009 at 7:32 AM  

Yeah, like the lubrication from the wet ink is gonna speed up the boot??? Get real - everyone know that since kernel 2.4.x ink has ZERO effect on i/o blocking.

Gord said...
March 12, 2010 at 1:50 PM  

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