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The Cost of Distributed Client Computing?
ialbert asks: "I only recently decided to install SETI@home on my mostly idle home computer. It got me thinking though, are those free processor cycles truly free? Has anyone had experience with processors dying prematurely due to a constant, heavy load, or is usage pretty inconsequential? What about other components, like harddrives? And how much does a 100% processor load increase your power bill versus a 1-2% idle load over the course of a year? It's easy to think of idle computers as an untapped computational resource, but what are the costs to the computer owners?"
While it is an interesting question, the reason you donate cycles to seti/columb rulers/cancer research/whatever is you love science and the progress of humanity.
:)
Its not about money.
Or to put it another way. How much CPU cycles are wasted on Pr0n, and how does this help society?
Excuse the Unicode crap in my posts. That's an apostrophe, and slashdot is busted.
I used to run a protien folding application on a spare Athlon I had. I thought it would help advance humanity. Then I discovered that the deamon I was running was spining my hard drive up and down all the time. Eventually the bearing gave out, and the disk platter came flying out of the case at high speed. It sliced through my cat and embedded itself in the oposite wall. The computer itself then caught fire when the drive motor over heated. It burnt my entire house and all of the contents, including a twelve thousand page thesis I had been working on (That work is classified, so I can't tell you what it was about). I stubbed my toe escaping, and a fire fighter died trying to put the fire out.
Just don't bother is my advice.
somebody worked this out when i started the e2 distributed.net team.
the figures
I've found that on my laptop, the cost of running seti@home cuts my battery life in half, so when I care about power I am sure to leave it off, however, when ever it's plugged in, it like the rest of my boxes are chugging away. When it comes to power costs I don't really care currently as I don't pay my electricity, it's included with my rent and believe you me I make good use of that.
As for premature death of CPU, being under heavy load should not hurt it, powering on and off often does far more 'wear and tear'.
Help Brendan pay off his student loans
Since I figured the cost of the processor running at 100% was insignificant compared to the cost of the hard drive constantly spinning instead of spinning down during downtime, I created a small RAM drive on my various computers where I ran seti@home so that the file access wouldn't affect hard drive usage. This worked equally well on linux and windoze. The only other thing to do was to create startup and shutdown scripts to create the ram drive, copy the files over, and start the process and then to copy off the files before shutdown.
Why do I h8 apple?
When Folding@Home is turned off, my power consumption for the entire system is 140W. When I activate Folding@Home, the Wattmeter reading jumps to about 190-195W.
So if you're concerned about electricity usage in your house, then yes, distributed computing sucks more power.
Homestarrunner.net -- It's Dot Com!
I'm kinda in a position to answer at least one part of this question.
CPu's, when idle, can use as little as 2-5W. When fully utilized, up to 40-50W (depending on the make/model/etc). So let's assume you have a middle of the road processor that has a difference of 25W between active and idle. (This is consistant with measurements on a PIII 800MHz, a little lower than middle of the road.)
Now, 25W * 24Hrs * 365 days * 1kw/1000W * $0.10/kWhr = $21/year. Roughly $1/year per Watt of additional power.
As far as breaking of components, as well as the system is cooled properly, I wouldn't think it would be a problem.
I demand a million helicopters and a DOLLAR!
Check this website for a breakdown of the energy costs.
http://www.dslreports.com/faq/2404
Right, and the standard in the ASIC industry is a 40 year lifetime minimum before electromigration will lead to failure in normal use (which means yo keep the chip in the allowed operating temperature range, regardless of if it's overclocked or not). That's 40 years. What hardware were you using 40 years ago?
Point is, even running chips hot, to a degree, (pun not intended) doesn't reduce their lifetime enough to worry.
Some of the other points, such as increased power use, and accelerated failure of mechanical components such as hard drives, are valid. But chip wear-out is a non issue -- you'd have to heat your chip past the point of system stability to get the em lifetime down low enough to care about it.
everything in moderation
Dell PIII-550MHz:
Athlon 1800+
So my computers seem to use about 20 extra watts under load compared to idle. That would amount to an extra $18/year if the app ran all the time compared to letting the machine idle all the time (@ $.10/kwh).
However, I usually power my systems off when I'm not using them. If my athlon system is off an average of 16 hours per day vs. running under load, that saves $65 per year.
My 17-inch CRT monitor used 74 watts. Turning off or suspending that would save a similar amount of money. Altogether, that would be about $10 per month, as you guessed.
Finaly a point where I have some numbers. I used to manage a net for a pharmaceutical company and we used to run the machines like most people. Turning them on when needing them and turning them off at night to save power. When we changed the SOP for computer use(on the teory that machines mainly die when turning on) to keeping the computers permanently on we had a decrease in service costs by 75%-80%. When these figures where held against the increase on the powerbill we saved ALOT of money (around 200 machines!!) When these figures where in we where given a pat on the back and a bunch of undrinkable flowers. When we also showed how much downtime we saved, we got a pat on the back an a full night on the town (with beer Free as in BEER ).
Yes, the grandparent post is incorrect.
Pentium IV CPUs have an internal temperture diode, just like every Intel chip since the Pentium II Deschutes core ( excluding early Celerons ).
As opposed to all chips before it, the Pentium IV will do more than just crash when overheating. It will dynamically reduce it's own clock speed to reduce power consumption. But this feature will only come into play when the cooling solution is unable to keep up with the processor ( IE: dead fan, extremely hot room ), and will not affect performance under normal conditions.
What the parent was referring to is the HLT instruction, which will cause the processor to do nothing and reduce power use. Most modern processors support it, and most modern operating systems ( including NT and Linux ) execute these instructions in an idle thread.
This is basically the concept of this discussion: will your computer run hotter under load rather than running idle HLT commands?
The answer is yes. What this means to you in terms of silicon lifetime is probably beyond the expertise of anyone here on Slashdot, so take every "insight" with a bag of salt.
Man is the animal that laughs.
And occasionally whores for Karma.