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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."
2002 called, it wants its Page 3 tech story back.
geek. lawyer.
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
If sharing a song makes you a pirate, what do I have to share to be a ninja?
vista with all the candy, on a machine which won't crawl? anything less then a 500w psu and it'll be under powered.
If you mod me down, I will become more powerful than you can imagine....
TFA lists all the states and how all this power management stuff is supposed to work... what it doesn't go into is how (or if) it actually does work. My experience is that it doesn't - I press sleep on my Windows XP PC ans all I get is a message telling me that the driver of my MIDI controller keyboard will not let the machine go to sleep!
And on my (admittedly very old) Ubuntu laptop the screen just blacks out for a couple of seconds and then comes back on again. When it was running windows it used to go to sleep fine, but the wireless wouldn't work when it woke up.
I guess other people's mileage probably does vary...
ccalam - acoustic versions of new songs.
anything less then a 500w psu and it'll be under powered.
Oh Bollocks. Vista might be shit and power hungry, but many laptops with a sub 100w psu will run it just fine.
There are shills on slashdot. Apparently, I'm one of them.
Sorry, I disagree.
PSU wattage (of course) has nothing to do with the speed of the machine. And while Vista is a power hungry beast, I don't think you can specify it's performance needs by stating the minimum wattage of the PSU. One can easily spec out a machine with a (say) 400W PSU that will run Vista just fine. You just need to pick speedy hardware that doesn't eat too much power. That means staying of the uber-high end stuff, which historically always had a bad power to performance ratio.
Besides, in a few months we'll have (more) budget-end PC's with the performance of today's mainstream ones which will run Vista, using an even smaller PSU.
*shakes head* You knew it had to be a Vista bash. Listen, Vista FULLY FEATURED works on 2-3 year old MIDRANGE hardware just fine.
Also, the Core 2 Duos are faster and consume less power than P4s. OMG CONTRADICTION. You haven't the faintest idea about this.
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?
Kid-proof tablet..
Is that why people don't blink at PS3s and X360s that eat 150-200W when they're idle? I guess that locks me and my 100W/system power budget out of gaming . . .
Seriously, what is it that uses up so much power? I've got a pretty standard dual-core system that idles at about 65W, and I can't push it beyond 150W even when I try.
The problem with any electronic device is they (to state the obvious) consume power so manufactureres have opted for approx 1W in standby mode. Unfortunately if you take a stereo amp plus active woofer a TV, HDD DVD recorder, set-top box (if you have one) and a least one game console (assuming they also consume 1W in standby) and you have a total of 7W consumption. Now extrapolate that to 10M people (I am being very conservative here) and that is 70MW overall consumption just for your entertainment system to do nothing.
Of course once you turn on your entertainment system the power consumption (taking the above example) can easily jump to 7GW even with fairly conservative systems. Now try the same simple maths with your fridge, microwave oven, oven clock (in fact any clock) and anything else that consumes power in standby. Add in lights even low wattage ones and your hot water heater (assume electrical off-peak not gas or solar) and the power consumption is massive. With regard to PC's and laptops consumption is dependent on what you have and can vary between 20W to over 1000W, It is possible to put a laptop in standby or sleep mode but this depends on if you are using your laptop as a standalone machine.
So what are we going to do about all that wastage? Well if you pay for your electricity and you want convenience then absolutely nothing and this is what most people will do.
There ain't no such thing as proprietary standards only proprietary formats. Standards are by definition open.
We used to standardize hardware interfaces. They stood the test of time, were well supported, and were low overhead. Writing drivers, including boot code, was no serious problem. We didn't need an emulator, virtual machine, etc.
Decent standards: IDE, VGA, PC serial interface, PC parallel interface, PC keyboard interface, UHCI, OHCI, etc.
Now we standardize an interface to non-standard hardware via ACPI. The OS is supposed to run ACPI code (a script) in a complicated interpreter. ACPI code is slow and buggy, and generally gets to do whatever it wants with the hardware. It's like making BIOS calls to do everything, but without even the minor advantage of native code.
This is especially painful for boot loaders. You can't run an ACPI interpreter in a 512-byte boot sector. You probably can't do it in any reasonable boot loader.
This is even painful for power management. For example, OLPC wants to suspend the CPU between every keystroke; that doesn't work so well if you need to run an ACPI code script to do it.
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.
I call BS. I have a C2D T7400-based laptop with 2GB RAM, Geforce GO 7600 and a 100GB 7200RPM-drive. It boots [a lot] faster with Vista than it does with XP (I've had both installed, currently using Vista). Vista has a lot of other annoying bugs though - mostly driver-related. A few NVidia-drivers made the Vista "Sleep" BSOD, but a newer beta fixed it for me. Another annoying bug on this (Zepto) laptop is that the NIC (not the WiFi) is flaky. Disabling it often makes it completely disappear :P
OTOH, there might be something about what you are saying. I think that a fast drive has a lot of say in booting Vista.
Any technology distinguishable from magic, is insufficiently advanced.
That means staying of the uber-high end stuff, which historically always had a bad power to performance ratio.
The problem with uber-high end stuff is that in two years it's mediocre and there is new uber-high end stuff that uses even more power. So old stuff uses relatively less power than new stuff, but still power consumption goes up over the years wehn you buy new computers. That trend must be broken.
-- Cheers!
Now tell me what ISA is..
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.
You are right it is possible to design devices that take a few milliwatts in standby however you have to realise that the power for the detection device (infrared, Blutooth, Wireless) comes from a transformer which has a low voltage tap that has to be converted to DC. Doing this does consume power even though it can be quite small however that plus the detection circuitry consumption does add up. Most commercial products have been designed to consume 1W or less and all the entertainment equipment I have has this specification. Of course once you switch all this on you don't have to worry about heating the living room in winter :-)
:-)
Just about all electronic equipment has what I would call useless add-ons such as digital clocks. Manufacturers are not stupid they want to sell their product and if they feel a clock or other non-essential add-on will make their product more attractive they will add this in as long as the total standby consumption is less than 1W.
The best way to switch off your entertainment system is via central isolator but do you want to keep reseting your timer clocks every time you power it up? You can switch off non-essential equipment by throwing the main power switch on each device that does not have a clock but this gets tedious.
This post actually sparked my curiosity on the latest consoles standby modes and surprisingly the PS3 came out well under 1W. The Wii came out at 8W (wow!) and the Xbox360 came out at 2W. However when the consoles were doing something the PS3 runs at approx 200W to the Wii's 17W and the Xbox360's 160W http://www.digitaldisplacement.com/?p=1907. If you only have a Wii then yes you can say the PS3 sucks for running power, however we are comparing a machine (Wii) that outputs Standard Def graphics compared to a machine that outputs to 1080p so the Xbox360 owners can take comfort that their machine does not use as much power (of course that does not include the hard drive or the HD-DVD so consumption could be much higher). If you have a gaming PC it is not advisable to say anything about any of the console running costs, "least ye be stoned to death"
There ain't no such thing as proprietary standards only proprietary formats. Standards are by definition open.
I'd say power consumption goes up very slowly on average. First it goes up fast, but so far there's always been some design breakthrough that drops it down to manageable levels again. Case in point: my X2 4400+ uses power roughly on the same level as my previous 2400+ XP, and significantly less when it drops down to idle usage (due to C'n'Q). I previously had a rather slow GF 6200, that had a passive heatsink. My current 7800GT uses a bit more power, but not so much it couldn't survive with just a heatpipe with no active cooling even when in heavy use, and it's much more powerful in terms of processing power.
True confidence comes not from realising you are as good as your peers, but that your peers are as bad as you are.
From: http://en.wikiquote.org/wiki/Linus_Torvalds
After one particularly eye-opening electric bill, I started putting everything on timers, save one computer and my fridge. If I'm asleep or not at home, the power gets cut.
Assume a kilowatt-hour cost $0.10. There are ~720 hours in a month (30 days/month * 24 hours/day). How many kwh is 1 watt running constantly?
720 h * 1 watt / 1000 (w/kw) = 0.720 kw-h
0.720 kw-h * $0.10 = $0.072 or a little over 7 cents per month.
I just don't know what you were thinking - did you mean to use pesos?
I agree that sleep is worthless for servers but it's great for pc users. For example my parent's dell c521 desktop when sleeping takes only 2-3w at the plug and 'appears' to be off (all fans stopped). It only takes a second or two to get back to the desktop and applications are left as they were. I also agree that hardware vendors (especially graphics and chipset makers) need to focus more on low power solutions not only for laptops but also for desktop and server machines. The cpu vendors have been working on it already and intel has been pushing things like centrino and santa rosa for laptops, but I see no reason why these technologies can't also be applied to desktops and even servers which typically get left on all the time if not quite often.