Keywords: battery power, sleepy state, sata link, mod enable, couple, watts, gnome, default, communication, controller, shave. Powered by TextRank.
my primary laptop has been running a flavor of windows for the last couple of months and I was getting really good battery juice (upto 6 hours). I decided to install the lastest ubuntu gnome 14.04 to checkout what the gnome guys were doing mainly, and because I missed the native bash stuff. But to my surprise the battery / power saving out of the box is terrible. I got a measly 2.5~3 hours with the default settings. So to enable longer battery life you need to do these:
This will stop the machine from electrically communicting with the PCI-E slots and save some watts. You need to edit /etc/default/grub and replace the line with the following
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash pcie_aspm=force drm.vblankoffdelay=1 i915.semaphores=1"
This mod enables the kernel AHCI controller to put the SATA link into a sleepy state when there is no communication. This will shave off a couple of watts from your power consumption as weel
sudo apt-get install pm-utils echo SATA_ALPM_ENABLE=true | sudo tee /etc/pm/config.d/sata_alpm
Here are some results for before and after these tweaks Running for 300 seconds (30 samples at 10 second intervals). ACPI battery power measurements will start in 180 seconds time
Time User Nice Sys Idle IO Run Ctxt/s IRQ/s Fork Exec Exit Watts 22:07:13 0.4 0.0 0.4 98.7 0.6 2 356 211 0 0 0 14.54 22:07:23 0.2 0.0 0.3 99.0 0.6 1 277 184 0 0 0 12.95 22:07:33 1.6 0.0 0.6 96.7 1.1 1 991 319 0 0 0 13.10 22:07:43 0.2 0.0 0.3 98.9 0.6 1 291 190 0 0 1 12.96 22:07:53 1.1 0.0 0.5 97.4 1.1 1 515 247 1 0 0 13.24 22:08:03 1.5 0.0 0.6 96.9 1.1 1 954 319 1 0 1 12.95 -------- ----- ----- ----- ----- ----- ---- ------ ------ ---- ---- ---- ------ Average 0.8 0.0 0.4 98.0 0.8 1.2 564.1 244.9 0.3 0.0 0.3 13.29 StdDev 0.6 0.0 0.1 1.0 0.3 0.4 299.1 56.2 0.5 0.0 0.5 0.57 -------- ----- ----- ----- ----- ----- ---- ------ ------ ---- ---- ---- ------ Minimum 0.2 0.0 0.3 96.7 0.6 1.0 276.7 184.2 0.0 0.0 0.0 12.95 Maximum 1.6 0.0 0.6 99.0 1.1 2.0 991.3 319.1 1.0 0.0 1.0 14.54 -------- ----- ----- ----- ----- ----- ---- ------ ------ ---- ---- ---- ------ Summary: 13.29 Watts on Average with Standard Deviation 0.57 Running for 300 seconds (30 samples at 10 second intervals). ACPI battery power measurements will start in 180 seconds time Time User Nice Sys Idle IO Run Ctxt/s IRQ/s Fork Exec Exit Watts 22:13:03 0.7 0.0 0.5 98.2 0.6 1 526 236 2 0 1 10.65 22:13:13 0.5 0.0 0.3 98.5 0.6 1 336 202 1 0 0 9.31 22:13:23 1.7 0.0 0.6 96.7 1.1 2 976 321 1 0 0 9.36 22:13:33 0.6 0.0 0.4 98.3 0.7 1 604 249 0 0 2 8.99 22:13:43 2.1 0.0 0.7 95.9 1.3 1 1171 359 0 0 0 9.10 22:13:53 1.0 0.0 0.8 97.6 0.7 1 950 341 0 0 0 9.37 22:14:03 1.7 0.0 0.6 96.9 0.8 1 677 287 0 0 0 10.22 22:14:13 1.5 0.0 0.5 97.1 0.9 1 924 304 0 0 0 9.00 -------- ----- ----- ----- ----- ----- ---- ------ ------ ---- ---- ---- ------ Average 1.2 0.0 0.5 97.4 0.8 1.1 770.5 287.3 0.5 0.0 0.4 9.50 StdDev 0.6 0.0 0.1 0.9 0.2 0.3 260.6 50.9 0.7 0.0 0.7 0.57 -------- ----- ----- ----- ----- ----- ---- ------ ------ ---- ---- ---- ------ Minimum 0.5 0.0 0.3 95.9 0.6 1.0 336.0 202.5 0.0 0.0 0.0 8.99 Maximum 2.1 0.0 0.8 98.5 1.3 2.0 1171.2 358.7 2.0 0.0 2.0 10.65 -------- ----- ----- ----- ----- ----- ---- ------ ------ ---- ---- ---- ------ Summary: 9.50 Watts on Average with Standard Deviation 0.57
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First published on 2014-10-17
Generated on 13 Dec 2024 at 12:11 AM
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