Best & Worst Case Power Usage On Ubuntu 12.04

Depending upon your hardware, the power consumption when running Ubuntu 12.04 LTS can either be at its best or worst. Here's a look at the two power consumption extremes of the Precise Pangolin.

Power consumption results in full for a range of mobile devices when running the latest development snapshot of Ubuntu 12.04 LTS compared to earlier Ubuntu Linux releases will be published on Phoronix next week. In this article are just the results from an old and newer laptop to illustrate Ubuntu 12.04 being in great power shape and at its best of the latest releases, while for older hardware the Precise Pangolin can be very power hungry.

The Ubuntu 12.04 LTS power consumption testing follows this week's Ubuntu 12.04 LTS boot performance results for six different notebooks/netbooks and the results going as far back as Ubuntu 6.06.1 LTS "Dapper Drake" from six years ago. Like the to-be-published power results, the Bootchart results were also mixed. For the newer hardware, the boot speed for Ubuntu 12.04 LTS tended to improve for some while on the older hardware it's seen faster days out of the older Ubuntu releases.

The first result is of an older Intel Pentium M notebook (full details will be in next week's power article) showing an unfortunate scenario where Ubuntu 12.04 LTS power consumption while idling is at its highest compared to Ubuntu 6.06/8.04/10.04/10.10/11.04/11.10. The idle power consumption was slightly higher than the Ubuntu 11.10 Oneiric Ocelot release and going through 13% more power while idling than did Ubuntu 10.04 LTS Lucid Lynx. The best case for this laptop was on Ubuntu 8.04.4 LTS -- the release that came three-years after the laptop was introduced -- where it went through 17.9 Watts rather than 23.1 Watts where it's at today (an increase of 29%).

While the older notebook above is now at its worse with 12.04, for some newer hardware Precise Pangolin does its best. The above preview is of an Intel Core i7 notebook where the power consumption of 12.04 LTS is clearly better than any release going back to Ubuntu 10.04 LTS! The power consumption of Ubuntu 12.04 LTS is down by nearly 40%. This is really a best-case example of Ubuntu 12.04 LTS improving the power situation as this Core i7 notebook was affected greatly by the PCI Express ASPM power regression I pointed out last year and then was finally fixed in a proper manner during the 12.04 cycle. There's also been other power optimizations that Canonical engineers and other upstream developers have been working on to try to improve the power consumption of Ubuntu Linux, but this largely benefits newer hardware.

The power consumption results of Ubuntu 12.04 LTS for a spectrum of mobile x86 hardware will be published next week. Besides looking at the average battery power consumption when idling, there will also be power consumption results when under full load of the CPU, GPU, etc. The power results largely go along with my comments made earlier this week where If You Have Old Hardware, Think Twice About Ubuntu 12.04 LTS. If you have older hardware (4~5+ years old, such as anything with a CPU that's 32-bit only), you're likely better off sticking with Ubuntu 10.04 LTS, similarly-aged distributions, or a lightweight Linux distribution rather than trying to run Ubuntu 12.04 LTS. The overall performance for this older hardware is largely in a free-fall.

Testing was facilitated in an automated manner via the Phoronix Test Suite. ACPI battery (and various USB-based power meter) monitoring can be done simply having the MONITOR environment variable set to sys.power (or all) when running a test (e.g. MONITOR=all phoronix-test-suite benchmark idle c-ray).