PC Power Management, ACPI Explained In Detail

DK writes "Computer performance has increased steadily in recent years, and unfortunately so has power consumption. An ultimate gaming system equipped with a quad-core processor, two NVIDIA GeForce 8800 Ultra, 4 sticks of DDR2 memory, and a few hard drives can easily consume 500W without doing anything! To reduce power wastage, the industry standards APM and ACPI have been developed to make our computers work more efficiently. ACPI is the successor of APM and is explained in detail in this article."

Comments

ACPI?

[crankyspice]

2002 called, it wants its Page 3 tech story back.

Not worth reading this crap

[Aranykai]

Im sick and tired of having to view 11 pages of adds to read an article that could easily fit on one. Easily 6 adds per page.

The Wikipedia ACPI article is better and doesn't shove crappy adds down your throat. http://en.wikipedia.org/wiki/ACPI

No, I didn't read the fucking article.

[adolf]

ACPI has been around for almost eleven fucking years. In-depth information about it can be had in all of the usual sources, from LKML to Wikipedia to decade-fucking-old back issues of Byte and PC Magazine.

News? Where?

Whatever

[Anonymous Coward]

Noones computer idles at 500 Watts, not even close. I wish people would check their facts before posting nonsense.

My 4 year old xenon dual processor (Thats two physical CPUs) PC with (~10 fans) with no power management support in the CPUs idles at 200 watts including powering the display and extraneous trinkets attached to the watt meter plugged into my wall.

All new PCs with multiple cores on single processors have power management features and use concideribly less power when idling.

Whats worse is the article spouts all kinds of mostly useless techno crap about power states without providing any context into what it means or useful information in terms of actual OS power settings one can configure to do something about their PCs power usage.

Sleep is worthless

[paul248]

Being able to put components to sleep is pretty much worthless if you want to run anything resembling a server. Hardware manufacturers need to focus less on sleep states, and more on making components consume less power while they're active.

A good first step is the 80plus initiative for power supplies. By increasing the power supply from 65-70% to 80-85% efficiency, you gain a decent amount of active power savings right off the top. If you care at all about conservation, make sure to check the efficiency rating of your next power supply.

The people at Intel and AMD have made great strides toward power efficient CPUs, which can scale back their clocks on-demand without noticeably hurting performance, but the real remaining problem areas are in video cards, RAM, and especially hard drives.

The ideal computer would consume almost zero power while sitting there doing "nothing," but be able to wake up at a moment's notice to handle requests from the user or the network. Power management should be hardware-based and completely transparent. ACPI is just a dirty hack that's becoming more useless as network accessibility becomes more important.

Re:ACPI is a disaster

[Bert64]

Whats worse is that...
There is a standard for these ACPI scripts, as you pointed out it's not great but at least there is one. There's also a compiler for them, written by Intel that complies with the standard.
But most hardware makers don't use Intel's compiler that complies with standards... They use Microsoft's compiler that completely breaks the standards, thus OS authors can't just implement according to Intel's published standards, they have to reverse engineer Microsoft's unpublished variations.