Slashdot Mirror
Ubuntu's Power Consumption Tested
RedDragon writes "Ubuntu 7.10 is due out on Thursday, October 18, and in addition to desktop 3D effects, GNOME 2.20, and other features is the use of the Linux 2.6.22 kernel with the tick-less (CONFIG_NO_HZ) kernel feature. But does this mean enhanced power savings when compared to past Ubuntu releases? Phoronix tested Ubuntu power consumption looking back 2-1/2 years at the six Ubuntu releases from Ubuntu 5.04 to the yet-to-be-released Ubuntu 7.10. Testing was done when the system was idling and then under load, and when the Lenovo notebook was powered via the battery and then again with the AC adapter. The Pentium M CPU temperature was also monitored. While Ubuntu 7.10 does include the tick-less kernel feature, more daemons and processes running by default on these modern Ubuntu releases is actually causing an increase in power consumption."
TFA doesn't specify error bars, which of course makes the results somewhat dubious. They list numbers to two decimal place accuracy (e.g. 48.00), but since all the numbers end in .00, I'm guessing those decimal places are not significant. In other words, the number are only good to within +/- 1 or +/- 2 or something like that. Considering that they are trying to compare numbers that are quite similar (27 to 33), their conclusions may not be reliable.
When comparing numbers, an estimate of the error is crucial. If the difference between two measurements is smaller than the error, then you cannot meaningfully say they are different.
Actually, I think it is rather impressive that 7.10 (which has eye candy on by default) has slightly less power consumption than 7.04 (no eye candy by default).
In other words, they increased features while decreasing (generally) power consumption. While it seems to be only about 1 or 2 watts lower (excepting battery idle where it is slightly higher), we are only talking 3-5 watts difference over 2.5 years of updates. In fact, it went down 4 watts using ac idle compared to 5.04, which I am sure had far fewer daemons/features.
Some of this may be better code etc. However, I think we should be giving the people who have been doing the coding here major Kudos for doing getting the most out of our computers (whereas MS wants us to quadruple our ram to use eye candy, they are doing it with the same amount of ram standard 4 years ago on a desktop, and keeping power down). I don't even want to think of what Vista must use in power.