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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."
Rest assured, it takes you four mouse-clicks to disable them. Every tried that under Vista?
very misleading healine. I RTFA and if you look at the nice graph, it actually shows a decrease in power usage since feisty and just about what the prior versions were. AC power consumption idling went from 31 to 29 from feisty to gutsy. while loaded, it went down slightly from 51 [feisty] to 50 [gutsy] the only thing that gutsy was higher in was battery discharge rate idle- it was at 22.26 while feisty was at 21.16. while loaded on battery it went down from 33.51 to 32.21 from feisty to gutsy.
Sigs are too short to say anything truly profound so read the above post instead.
Vista takes 5.
1: Right click on desktop.
2: Select Personalize
3: Select Theme
4: Select Windows Classic
5: Click OK.
Laptop users may want to stick with 32-bit Ubuntu, since the CONFIG_NO_HZ (tickless kernel) option isn't available in 64-bit kernels yet.
If you're feeling adventurous, patches here: http://www.kernel.org/pub/linux/kernel/people/tglx/hrtimers/
Hail Eris, full of mischief...
E pluribus sanguinem
I just don't trust anything that bleeds for five days and doesn't die.
The HPET stuff is now scheduled for merge into the 2.6.24 kernel. I've had to patch my earlier kernels to get HPET, which as you say is really necessary for tickless to do its stuff. The article suggests that this is a stock Gutsy installation. But then again, most distros do a bit of custom patching of their kernels. In particular, Gentoo does not include the HPET patch.
So the question here: Does the Gutsy kernel have the HPET patch applied?
If not, then these power numbers are definitely pessimistic, presuming that they move to an HPET kernel (2.6.24+) as it's available.
Someone here with a Gutsy system should run "powertop" on it, and let us know. IIRC, powertop suggested that I use the HPET, and with a little digging I found that a patch was needed, and took care of it.
The living have better things to do than to continue hating the dead.
Does this answer your question?
/boot/config-2.6.22-14-generic
$ grep HPET
CONFIG_HPET=y
CONFIG_HPET_MMAP=y
# CONFIG_HPET_RTC_IRQ is not set
CONFIG_HPET_TIMER=y
CONFIG_HPET_EMULATE_RTC=y
$ dmesg | grep hpet
[ 8.328261] hpet0: at MMIO 0xfed00000, IRQs 2, 8, 0
[ 8.328266] hpet0: 3 64-bit timers, 14318180 Hz
[ 0.744000] Time: hpet clocksource has been installed.
So if you start your number crunching computer program and push "Start" and it takes 15 minutes on the first CPU and over 40 on the second, presuming you were to turn your computer off when the program finished, you'd have used the first one for less than half the time.Not really; most laptops and many desktops can scale their speed. If you want to accomplish 15 minutes of work in 40 minutes, you can either throttle the newer CPU's speed (presumably using much less than the full power rating) or replace it with an older processor which is not as efficient (and therefore equally as fast, but likely to use more power).
If you scaled your new one down to less than the speed of your old one, you'd get more time out of it. So if you're watching a DVD and not really accomplishing a lot of "work", that's what you'd do to get more time than the old laptop but still have more processing power.
Remember, 3GHz refers to CPU clock cycles per second - an old thunderbird gets less done in a cycle than a new Athlon64 X2. So even a 1.4GHz single core Athlon64 is faster than a 1.4GHz Thunderbird. So you can slow the new one down from 1.4GHz and still get the same work out of it. A DVD might be choppy at 500MHz on a really old machine, but a brand new state of the art processor might be able to deal with it just fine at 500MHz, even if both machines have similar bus and memory speeds and come with the same MPEG decoding video card.Actually, this is a characteristic of both transistors and vacuum tubes, and therefore literally all CPUs do this. The amount of voltage supplied to the CPU is supposed to be constant - but the more transistors you use, the more amperes are drawn (volts * amps = watts). Relative to peak power usage, the difference between two idle CPUs is likely negligible, even for older models.
Find a computer with a variable speed CPU fan, and listen for it to shut off when you're idling. Less heat means less power.