Transcript Computer Power Consumption

Computer Power Consumption
Created By Paul Briskey
February 18, 2008
Outline
•
Computer Power States
•
Computer Power Consumption Factors
•
Notes On Energy Star
•
Power Test – System Configuration
•
Power Test Results
•
Conservation Steps and Software Notes
•
Changing Power Management Settings
•
Sources
Computer Power States
Power State
Description
S0 (At Desktop)
Normal working state (either idle or active).
Computer is ready to go.
S3 (Sleeping)
Monitor, HDD, and other peripherals are turned off
but RAM is still on and holding data. Fastest to wake
up.
S4 (Hibernating)
All data in RAM is stored to the HDD and everything is
shut down. Medium amount of time to wake up.
S5 (Power Off/Mechanical Off) Computer is off but still plugged in. Must go through
full boot process.
G3 (Power disconnected)
Power strip is off or computer is not plugged in.
Must go through full boot process.
Computer Power Consumption Factors
• Everything makes a difference
– Power consumption is based on voltage levels and current
requirements. These will vary drastically not only with
component attributes (i.e., processor speed), but also between
brands.
– Power management options in the operating system as well as
in the motherboard BIOS also change consumption.
• Performance often precludes power savings
– Increases in speed result in more power use. For example, an
increase in memory speed causes it to become unstable so the
memory voltage is increased. This directly results in more
power use.
Notes On Energy Star
For Computers/Motherboards
• Energy Star is a product certification that manufacturers
can apply for.
• Each product type (desktop, server, etc.) has several
categories, each with different qualifications.
• Compliance is taken very seriously since ONE failed test
at any time prohibits certification for the failed product
indefinitely.
• Test conditions are specified by the manufacturer.
Therefore, an E-Star compliant system might only pass
when specific parts are used and many system options
are disabled.
Power Test – System Configuration
Gaming System
Multimedia System
Energy Star Board
Board
Intel D975XBX2
NVIDIA nForce660
Processor
Intel Core2 Extreme
(45nm, 1.165V)
Intel Pentium Extreme Multi-core
(65nm, 1.525V)
RAM
2GB PC2-5300 (1.8V)
4GB PC2-6400 (2.2V)
>2GB
HDD
500GB SATA II
200GB SATA II
300GB SATA II
500GB SATA II
240GB IDE
120GB IDE
>2 HDD
Graphics Card
GeForce 8800GTS-512 GeForce 7900GTX-512 >128MB dedicated
Sound Card
X-FI Xtreme Music
X-FI Xtreme Music
None
Other
TV Tuner Card, PCI
USB Card, 4- 120mm
and 1- 140mm case
fans, DVD ROM (IDE),
DVD-RW (IDE)
TV Tuner Card, 2120mm case fans,
Wireless-G Network
Card, 13in1 Card
Reader
TV Tuner/Video
Capture Card
Note: Parts list is not exhaustive. Energy Star configuration for Class C desktop board
Power Test Results
Power State
Gaming System
Multimedia System
E-Star Board*
S0 (Active)**
250W
300W
-
S0 (Idle)
163W
212W
<95W
S3 (Sleep)
7W
6W
<4W
S5 (Off)
6W
5W
<2W
kWh/
month
Cost/month
@ $.10/kWh
kWh/
month
Cost/month
@ $.10/kWh
kWh/
month
Cost/month
@ $.10/kWh
S0 (Idle)
117.36
$11.74
152.64
$15.26
<68.4
<$6.84
S3 (Sleep)
5.04
$.50
4.32
$.43
<2.88
<$.29
S5 (Off)
4.32
$.43
3.6
$.36
<1.44
<$.14
*E-Star board power requirements are based on the Intel Desktop Class C standard (classes A and
B have more stringent power requirements).
**Active Test: Running 3DMark06
Conservation Steps & Software Notes
To Conserve Energy:
• Turn your computer off at night. (Basic)
• Change power management options on your computer.
(Intermediate)
• Disable unnecessary motherboard options. (Advanced)
• Disable unused hardware in the device manager or set it to enter
low power mode when not used. (Advanced)
Using Software:
• You can download software to change power management options for
you. Many systems already include this.
• If you can do it yourself (it is very straight forward) you will avoid another
program running in the background slowing your computer down.
• This software is not capable of changing any motherboard options in BIOS
Changing Power Management Settings
1. Right click on the
desktop and select
“Properties”
2. Select the “Screen Saver”
tab and click “Power…”
3. Select a power scheme and hit OK
 Explore this dialogue to find other options for power saving
Sources
Bolioni, Thomas, et al. “Energy Star* System Implementation.” April 2007.
Intel Corporation. 18 February, 2008.
<http://cache-www.intel.com/cd/00/00/33/90/339085_339085.pdf>