SIGs/PowerManagementHWtable

= Power consumption of hardware components = -


 * Please, feel free to add missing information if you find out new one.
 * The table is appropriately descending sorted (sort key is power consumption)

= Comments to the components =

CPU
The CPUs are one of the biggest power consumer. We should focus on more effective code (code consumes less CPU-time) what will affects power consumption of processors. On the other side it will improve performance on computers containing low energy processors (e.g. Atom).

Graphics cards
The graphics cards (GC) are the main power consumer in desktops. This points to huge potentials to save power. Matthew Garret did changes to some F11 drivers to be power saving:
 * LVDS re-clocking - which basically reduces the refresh rate of the display when the screen is idle for LCD displays (this works without any visual impact as the refresh rate is reset as soon as there is activity)
 * GPU clock reduction that's in the intel and ati driver. This reduces GPU clock if there is no 3d activity
 * GPU powerdown

Motherboard and Memory
Motherboards, memory and bus are not investigated yet ...

Disks
HDD - the HW table has discovered the disks are more less behind our focus. The HW manufacturers solve PM in the firmware (e.g. GP and Green series of Western Digital). The WD disks of GP and Green series adjust dynamically spin dependent on load to save power.

We are able to optimize number of i/o operations and spin down the disk (no info what causes APM values 128-254 - see hdparm -B). There is no more things to do.

HDD versus SSD - Comparison of power consumption HDD and SSD disk doesn't prioritize SSD disks. You can read on Tom's hardware sites.