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Intel Releases Several Projects to Help Save Power
Posted by
Zonk
on Fri Sep 21, 2007 11:39 PM
from the by-the-power-of-greyskull dept.
from the by-the-power-of-greyskull dept.
GeekyBodhi writes "LessWatts.org is Intel's new website that hosts several power saving tools. As Linux.com reports, it also shares tips and tricks to help optimize power consumption on hardware from portable devices running on batteries to large data centers. 'LessWatts.org is not about marketing, trying to sell you something or comparing one vendor to another. LessWatts.org is about how you can save real watts, however you use Linux on your computer or computers.' As reported on Slashdot earlier, this isn't the first time Intel has tried to help Linux users cut their power bills. In May, the company launched the PowerTOP program that monitors individual processes to keep track of power consumption. The project comes at a time when more vendors are pre-installing Linux on handhelds and laptops." Linux.com and Slashdot are both owned by SourceForge.
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Intel's PowerTOP Extends Linux Battery Life 113 comments
DuracellFan writes "Intel recently released its PowerTOP utility, which builds on work done by kernel developers to make the Linux kernel power-efficient. PowerTOP gives a snapshot of what apps are consuming the most power. The PowerTOP website also hosts patches for several Linux apps and the kernel. In the Linux.com article, lead PowerTOP developer Arjan van de Ven of Intel says that PowerTOP could soon show which applications keep the disk busy." Linux.com and Slashdot are both part of OSTG.
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Fewer Watts (Score:2, Informative)
Re: (Score:3, Funny)
Re: (Score:2)
powertop... (Score:5, Informative)
Regardless, Powertop actually is a useful tool, and it's helped me get much better battery life out of my T61 running Ubuntu.
Re: (Score:3, Informative)
Interesting question... (Score:4, Interesting)
Re: (Score:2)
Re:Interesting question... (Score:4, Insightful)
power supply calculator (Score:2)
eXtreme Power Supply Calculator Lite v2.5 [outervision.com]
Re:Interesting question... (Score:5, Informative)
Basically Windows consumed significantly less power than Linux (about 30-40% less). From the lesswatts site it is good to see that more power saving will be in the Linux kernel in the 2.6.24/25 timeframe (eg SATA power saving) as well as user space (eg not polling SATA cdroms every 2 seconds looking for media changes). I guess we'll be seeing those updates in Hardy Heron.
for desktop, power supply is biggest waste (Score:4, Informative)
Re:for desktop, power supply is biggest waste (Score:5, Informative)
Re: (Score:2, Interesting)
Re: (Score:2)
Re:for desktop, power supply is biggest waste (Score:4, Informative)
You'll find a variety of statements about this running around on the web. It's true that a switching power supply is a wildly nonlinear device (which is why, for example, you can't test it without a load). But there's no simple, reliable rule for when it will be most efficient. You'll hear some people saying a PS is most efficient when used near 100% of its rated capacity, and others who say 50%. Some usenet folks did systematic measurements (you can probably turn up the thread on google groups, I don't have it handy), and they found that basically none of these statements was generally true. There was no clear relationship between % load and efficiency that held true across a variety of power supplies. When people say that it's most efficient when almost 100% loaded (I know, you didn't say that, but other people do), there are two things to keep in mind: (a) it's not necessarily true, and (b) even if it was, you wouldn't want to design your system so that it used almost 100% of the PS's rated power. What typically happens if your PS is on the ragged edge of having enough power for your system is that you get random failures to boot which are hard to reproduce. The reason is that booting tends to require a lot of power (spinning up the drives, running the CPU full-out), and may go over what the PS can supply.
The main thing is to get an 80PLUS power supply. Not only can you be sure it will be efficient, but it won't contain any lead.
What Intel is doing seems laudable, but it seems like it's likely to be a very time-consuming way for an individual to cut one watt off of their system's power consumption. You want to pick the low-hanging fruit first. Get a power consumption meter such as a kill-a-watt, and take some measurements. I used to have a pair of speakers that drew 12 W, even when the computer was off, and I didn't know it. If you've got a CRT, replace it with an LCD. Another big issue is doing your word processing on a machine with a video card that gets hot enough to fry an egg on.
The other big issue on Linux is poor support for power management. There are some success stories, such as the fact that the kernel automagically supports AMD cool'n'quiet, but in general, there are serious problems with sleep and hibernation on linux, and the reason is that manufacturers of peripherals refuse to publicly release the documentation for all the registers that need to be saved in order to restore their states when the machine wakes back up. Personally, I've never had any luck with sleep or hibernation on any machine I've ever installed linux on.
move heat away of power supply (Score:3, Interesting)
Instead use a heat sink that have a vertical cooler like Zalman CNPS95
what? (Score:2)
Real watts? You mean as opposed to imaginary watts?
Re:what? (Power Factor) (Score:2)
Shove an AC current into an RC circuit tht is resonant. Then you have
lots of Imaginary watts!
What about... Windows users :( ? (Score:3, Interesting)
Please?
Grammar (Score:4, Informative)
Of the 291 million transistors (Score:5, Interesting)
on modern Intel CPUs, the overwhelming majority are used to compensate for the fact that the CPU is ridiculously faster than the memory to which it interfaces. IOW, the cache. These CPUs consume between 80 and 120 watts [intel.com] of power. The reduced power versions use only 50.
By way of comparison, the 1 GHz AMD Geode runs on about 1 watt of power, and ARM processors can get by for even less.
By way of further comparison, a register to register transfer can be completed in 1/2 clock cycle. Contrast this with a read-modify-write memory cycle where a word is fetched from one memory location, modified, and written to a distant location, which will take 4 memory cycles (which typically runs at 1/2 or less of the clock speed of the CPU).
The power consumption problem is due more to the fact that compensating for this difference in speed requires a large SRAM cache on the die. And even then, it's not perfect - if you do things which routinely involve cache misses (such as video encoding, etc...) the CPU is stuck operating at the effective speed of the memory bus.
The key to reducing CPU power consumption is to use lower-latency memories, which require smaller on-die caches for a given performance level. We could double the throughput of DDR SDRAM by simply demultiplexing the address and data busses, similar to the way SRAM functions. There's no requirement in the underlying storage structure of DRAM to require separate row and column addresses; it's just a historical artifact. Originally, before DRAM and SDRAM became popular, computers were built with SRAM because its lower latency allowed even slow CPUs to work efficiently. But DRAM promised lower cost (via fewer bus lines) and lower power consumption (bits stored in charged capacitors, rather than cross-coupled transistors), at the price of latency, and the rest, unfortunately, is history.
Linux-Ecology-HOWTO: More than Power Saving (Score:2)
Re:less? (Score:4, Funny)
Or, they could have gone the nostalgia route and used "WattsYouTalkinAboutWillis.com"
Re: (Score:2)
I'd say the desktop platform is in a great position. speed has gone way up and cost is way down, and we have more options then ever in the history of computing. I propose you are
Re: (Score:3, Informative)