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?"

Re:Wear Out

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.

Re:Processors dying...

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.

missin the point.

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? :)

Re:missin the point.

>How much CPU cycles are wasted on Pr0n

I have a computer and Internet connection specifically for pr0n, so my CPU cycles are not "wasted" but "perfoming its main function".

Inherent danger

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.

Re:Power

A while back I plugged a variety of appliances into an ammeter to see what they consumed. Here is what I got for a couple of computer systems:

Dell PIII-550MHz:

• Idle - 39W
• Unreal Tournament - 57W
• Compiler Build - 56W
• Powered Down - 2W

Athlon 1800+

• Idle - 99W
• Unreal Tournament - 118W
• Powered Down - 5W

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.

the math

somebody worked this out when i started the e2 distributed.net team.

the figures [everything2.com]

Power

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'.

ram drive

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.

Re:ram drive

Hard disks are more reliable in my experience than CPUs too.

You living in Bizarro world? Or are you just an overclocker?

How could a mechanical hard drive be more reliable than a solid-state CPU? Hard drive failures are a well-known problem, which even makes its way into primetime sitcoms. Everyone knows someone who's drive crashed. Rumors fly that the latest batch of Seagate or Western Digital may have jinxy spindles.

But stop a pedestrian and ask him when he last heard of a CPU burnout- you'll get a puzzled look. Since I don't OC, I've never lost a CPU. But my stack of dead IDE drives is tall on the bookcase.

Even amoung Slashdot users, I'm sure a show of hands would reveal that far many more people have suffered from unpredictable failures of an HD than a CPU.

(Google says that "hard drive reliability" is nearly twice as common a topic as "CPU reliability")

The most you`d hope to get out of it is `yes, there are other civilisations out there`, and I already know that.

You'd get two things, sequentially:
1. Not just knowledge, but PROOF. That you followed Sagan's "billions & billions" calculations is one thing. That everyone else KNOWS its true is another. Potentially, this could change the terrestrial balance of power. (More likely, resistant groups will deny the proof, but they'll at least be marginalized somewhat)

2. Later you'd get actual translations of the messages. Who could predict the value of alien wisdom and folly?

50 Watts increase at 100% CPU Load

I have a Pentium 4 @ 2.6GHz, overclocked to 3.2GHz. My power strip is plugged into a great little device: the Kill-A-Watt [ccrane.com] wattmeter. I can track my electricity usage over time by Volts, amps, Watts, VA, and it keeps a log of the kWh consumed by a particular device.

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.

Never had a problem with that...

I've been using http://www.distributed.net/ [distributed.net] on and off for a few years now and i've never had a problem with any of my processors. However I usually upgrade my cpu/mb every 3-4 years, so if you have or keep your systems longer i'd imagine any burnouts would be due to "just an old cpu" and not from the constant use. Then again I don't plan or expect my hardware to last forever.

As far as the power bill goes. I currently have a desktop, laptop, wireless router/hub and zaurus going the majority of the day - at least the systems are always on since I am too lazy to turn them off and have no need too. I also live with my girlfriend who runs the haridryer every morning and must have every light on in the house to check her makeup with. At the end of the month we get our power bill of $45-50 - which in my opinion is not a lot. We're also in California for the record.

Some Measurements.

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.

Energy costs

Check this website for a breakdown of the energy costs.

http://www.dslreports.com/faq/2404

Tough one

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?

Those are all surprisingly complex and computationally intensive questions. In order to find the answer, I'll soon be releasing "@home@home", a distributed application designed to calculate the true cost of itself.

There is a possible issue with solid state stuff

Many have pointed out that chips essentially don't wear out, but that's only in a world where every motherboard has a perfect design. In reality, given any motherboard, there will be some bad parts of the design and the lifetime may indeed be effected by how much it is stressed, especially those with an error in the design as regards to heat dissapation though underspeced drivers can be a big issue to. Also, many use capacitors whose values change after a few years due to chemicals cooking out of them. This is why many of the cheaper motherboards on the market will just stop working or become unreliable after about 3 years. If those motherboards are run hotter for a larger percentage of time, certainly there will be a reduction in life.

Even so