peirce@outpost.UUCP (Michael Peirce) (02/11/91)
In article <6140@idunno.Princeton.EDU>, rlwald@phoenix.princeton.edu (Rob Wald) writes: > > > What is the current wisdom on leaving your computer on? I have a IIci > with a 105mb Quantum drive (if it makes a difference). Is it better to > leave it on if I'm going to use it several times a day? Overnight? > Thanks. I also have a IIci w/ 105mb Quantum. I've been leaving it on almost constantly for the last six months - mostly so it can be part of usenet and poll every hour. Sometimes I turn off the monitor mainly to cut the heating of the room in warm weather. In a previous life I left my Mac II and its monitors on for about two years, turning it off only when on vacation or over long weekend. Never a trouble. -- michael -- Michael Peirce -- outpost!peirce@claris.com -- Peirce Software -- Suite 301, 719 Hibiscus Place -- Macintosh Programming -- San Jose, California 95117 -- & Consulting -- (408) 244-6554, AppleLink: PEIRCE -- Ask me about AppSizer (and ask Claris about Public Folder :-)
sl242030@silver.ucs.indiana.edu (Robert P. Humphrey) (02/11/91)
Actually, it's a matter of picking what you want, and sticking with it. Outside of an environmental standpoint, if you access your computer more than once every couple of hours, it's best to leave it on all the time, unless you're going to be away for several days. But a computer actually customizes itself to its user; if you leave it on all the time, and then start turning it on and off every time you use it, you'll be prone to power spike problems; if you usually turn it on and off periodically, and then leave it on for long periods of time, it will be prone to thermal problems. Just pick a system that meets your usage, and be sure to stick with it. **DiskDoctor**
johnston@oscar.ccm.udel.edu (William D. Johnston) (02/11/91)
(Jonathan Pace) writes... [ ... less wear and tear to leave the computer on, but ... ] > If you're concerned about the environment (no stand taken here) you should >turn it off. If everyone left their computer on all the time it would use >billions of kWh each year. My SE/30 manual states that the *maximum* power consumption of 75 watts. This is less than the light bulb in the lamp next to my computer. While I whole-heartedly endors the notion of energy conservation, I prefer to do it by telecommuting ... leaving a computer on all day can actually make a significant contribution to solving the energy crisis. -- Bill (johnston@oscar.ccm.udel.edu) .. too bad we can't solve the gulf crisis with a "flame-war" ...
jp48+@andrew.cmu.edu (Jonathan Pace) (02/11/91)
Marc Kaufman writes: > it takes about 600,000 Macs being left on all year to use 1 billion kWh of > electricity. Isn't that about the number of Macs (if not more) that have been sold to date? I did say "if everyone". Jon
waire@seas.gwu.edu (Timothy A. Waire Jr.) (02/11/91)
In article <MbhYnfa00WB28HpFRV@andrew.cmu.edu> jp48+@andrew.cmu.edu (Jonathan Pace) writes: >>Marc Kaufman writes: >> it takes about 600,000 Macs being left on all year to use 1 billion kWh of >> electricity. > Isn't that about the number of Macs (if not more) that have been sold to >date? I did say "if everyone". > Sorry, I think the actual number is much higher then that. According to a MacWeek (02.05.91) Apple Forecast, there will be 2,280,000 projected Mac units shipping in 1991. -- Timothy A. Waire, Jr. (Whitegold) Executive Office of the President INTERNET: waire@seas.gwu.edu Office of Management & Budget The George Washington University Wash., D.C. 20503 Electrical Engineering & Computer Science Voice: 2023954922 Fax: 2023953910
jkain@bronze.ucs.indiana.edu (Jeff Kain) (02/12/91)
sl242030@silver.ucs.indiana.edu (Robert P. Humphrey) writes: >But >a computer actually customizes itself to its user; Huh? -- "Swing is a feeling... Everything else is just style." --Capt. Swing jkain@bronze.ucs.indiana.edu -- "Swing is a feeling... Everything else is just style." --Capt. Swing jkain@bronze.ucs.indiana.edu
wnn@ornl.gov (02/12/91)
In article <6140@idunno.Princeton.EDU> rlwald@phoenix.princeton.edu (Rob Wald) writes: > > What is the current wisdom on leaving your computer on? The stress of thermal cycling may reduce component life if you keep turning your computer off and on every hour. On the other hand, most components are reated for mean time between failure (MTBF) not taking into account how many power-on cycles you go through. If you turn your computer off and on less than four or five times per day, total up time probably has a greater influence on the life span of most of the components. Many electronic components, such as CRTs or capacitors decay over time and mechanical parts, such as disk drive bearings wear out. At the minimum, turn your computer off over night. A week has 168 hours, most people work only 40 to 50 hours. So you can expect your hardware to last about three times longer, even figuring in a rather generous discount for thermal stress aging. And, of course, you help conserve a lot of energy that way, which will not only save you or your employer money, but will also help reduce environmental impacts! Moreover, while your computer is turned off, it is much less likely to be damaged by a power spike. In terms of power consumption, it is even more important that you turn laser printers off when not in use. They generally consume much more energy than a personal computer because they keep their fuser rollers hot all the time. Actually, some of the older models of the HP LaserJet can even suffer damage when left turned on for several day without use. The constant pressure and warmth one one side of the rubber rollers causes them to be deformed. The myth that it is better for computers to be left powered on may stem in part from a mistaken comparison with mainframes, most of which do batch processing during the night anyway. Modern desktop computers are designed for frequent power cycling and they use components that are quite different from those in their elder brothers and sisters. Some mainframe CPU's are cooled to cryogenic temperatures and can only stand a few dozen or hundred cycles of warming up to room temperature and being brought down to operating conditions again. The entire debate reminds me a little bit of the one about fluorescent lighting. In that case an old myth holds that restarting fluorescent lamps takes more energy than leaving them on for several hours. Just think how much power that would be in the couple of seconds for starting them up and what heavy wiring it would require to supply that power. Our wall switches and power distribution boxes would resemble a power company switchyard! Wolfgang N. Naegeli President, MacClique--East Tennessee Macintosh Users Group University of Tennessee & Oak Ridge National Laboratory Internet: wnn@ornl.gov Bitnet: wnn@ornlstc Phone: 615-574-6143 Fax: 615-574-6141 (MacFax) QuickMail (QM-QM): Wolfgang Naegeli @ 615-574-4510
craparotta@craparotta.enet.dec.com (Joe Craparotta) (02/12/91)
Usually if your not going to use if for more than 6hrs.. I would shut it off.. I know alot of people who run BBS's and haven't had any problems over the years.... Joe Craparotta Craparotta@level.dec.com --or-- ...!decwrl!level.dec.com!craparotta --or-- craparotta%level.dec@decwrl.dec.com discalimer: The above are my Personal views and do NOT represent those of my EMPLOYER.. They don't listen to me anyway.. :-))
auvvidl@auvc14.tamu.edu (Mike Vidlak) (02/13/91)
Maybe I missed the postings, however, how about a reply from some technical folks regarding this subject? Should we leave our machines on all the time or turn them off if not in use for ~6 hours? -- _______________________________________________________________________________ Michael D. Vidlak Internet, NeXTmail: mvidlak@cs.tamu.edu Department of Computer Science uucp: uunet!cs.tamu.edu!mvidlak Texas A & M University BITNET: MDV9327@TAMVENUS College Station, TX 77843-3112 CSNET: mvidlak%cs.tamu.edu@RELAY.CS.NET ---Not an official document of Texas A&M---
gillies@m.cs.uiuc.edu (Don Gillies) (02/13/91)
A Mac SE/030 takes about 60 watts of power (average, turned on). A color Mac II takes about 120 watts of power (average, turned on). These quantities were derived by measuring average DC current through a full-wave bridge on an ohmmeter, then naively multiplying by 120v. Do you leave light bulbs on 24 hours a day like this? That's 1.5 - 3 --
gillies@m.cs.uiuc.edu (Don Gillies) (02/13/91)
Let's put this in perspective. Leaving a 60-watt bulb on for a (? day ? or was it an hour) generates 5 lbs of CO2 at the power plant. If you believe in the greenhouse effect, turn it off please. --
espen@math.uio.no (Espen J. Vestre) (02/14/91)
In article <1991Feb13.034522.6718@m.cs.uiuc.edu> gillies@m.cs.uiuc.edu (Don Gillies) writes: > Let's put this in perspective. Leaving a 60-watt bulb on for a (? day > ? or was it an hour) generates 5 lbs of CO2 at the power plant. If > you believe in the greenhouse effect, turn it off please. > -- At this time of the year, that just doesn't matter (It's still winter in Illinois, I assume?). Almost all the energy that a light bulb or a mac consumes, is turned into heat. So what really matters is what temperature you keep in your office/home. If the temperature is low enough (most people keep it too high in winter), it doesn't matter what way you generate the heating (provided of course, that you don't have a local heating system that is more environment-friendly than your local power plant). Btw, I once heard of a Xerox Lisp Machine (> 500 Watts) that was used to heat a cold office during the winter :-) ----------------------------------------- Espen J. Vestre Department of Mathematics University of Oslo P.o. Box 1053 Blindern N-0316 OSLO 3 NORWAY espen@math.uio.no -----------------------------------------
rubin@oak.cis.ohio-state.edu (daniel j rubin) (02/15/91)
>A Mac SE/030 takes about 60 watts of power (average, turned on). >A color Mac II takes about 120 watts of power (average, turned on). > >These quantities were derived by measuring average DC current through >a full-wave bridge on an ohmmeter, then naively multiplying by 120v. > >Do you leave light bulbs on 24 hours a day like this? That's 1.5 - 3 >-- I can't believe that a computer itself is going to consume 120 watts of electricity. Now I can understand how the MONITOR would soak up the watts, but the CPU of a plus and a II would be pretty close to each other I would think. The most common source of electronical failure is due to cracks in the traces on the PC boards due to thermal expansion which results in replacing the entire board. If you are concerned about money and the environment, I would turn your monitor off and always leave your CPU on. Just a suggestion. I just want to throw in the comment that if you want to save the environment think about alternative power sources like nuclear ( the same people who complain about the green house affect seem to shoot down the only viable option at this time - frustrating ). - Dan Rubin
gt4586c@prism.gatech.EDU (WILLETT,THOMAS CARTER) (02/15/91)
The most cogent reason I've seen for turning off the mac is the possibility of excessive wear on the spinning hard drive. How well engineered are the hard drives in that regard? How many spin hours can they be expected to last? Lastly, is it feasible to create a "sleep" mode for your computer in which the hard drive spins down but the CPU stays on to keep warm? -- thomas willett Georgia Institute of Technology, Atlanta gt4586c@prism.gatech.edu "Violence is the last refuge of the incompetent." - Salvor Hardin (Foundation)
wnn@ornl.gov (02/16/91)
In article <88434@tut.cis.ohio-state.edu> rubin@oak.cis.ohio-state.edu (daniel j rubin) writes: >The most common source of electronical failure is due to cracks in the ^^^^^^^^^^^ >traces on the PC boards due to thermal expansion which results in replacing >the entire board. Obviously you don't have much experience in PC maintenance. Such cracks are *VERY* rare. What's common are "cracks" in the solder points where components are attached to the traces. In many cases, reheating those points solves the problem. If the component in question has been damaged, or another one in the affected circuit has burned out because it experienced overload, replacement of the affected components does the job. Even if a trace has cracked, it can usually be fixed easily with a jumper wire. >If you are concerned about money and the environment, I >would turn your monitor off and always leave your CPU on. Just a suggestion. >I just want to throw in the comment that if you want to save the environment >think about alternative power sources like nuclear Aha! One of those nukies who wants to convince the world to squander energy to justify the need for nuclear power plants. >( the same people who >complain about the green house affect seem to shoot down the only viable option ^^^^^^^^^^^ >at this time - frustrating ). Several independent government funded studies have come to the conclusion that conservation is the most viable option! Continuing improvements in wind and solar have made them a viable option too. If we don't care whether we are wasting energy and money, we will use nuclear, but if we would like to save some money, and are willing to use energy more wisely, alternative sources will easily supply an increasing proportion of our needs. Follow-up on this issue to talk.environment Wolfgang N. Naegeli Internet: wnn@ornl.gov Bitnet: wnn@ornlstc Phone: 615-574-6143 Fax: 615-574-6141 (MacFax) QuickMail (QM-QM): Wolfgang Naegeli @ 615-574-4510
russotto@eng.umd.edu (Matthew T. Russotto) (02/16/91)
In article <22085@hydra.gatech.EDU> gt4586c@prism.gatech.EDU (WILLETT,THOMAS CARTER) writes: >The most cogent reason I've seen for turning off the mac is the possibility >of excessive wear on the spinning hard drive. How well engineered are the >hard drives in that regard? Most hard drives fail during spinup and spindown, or die due to stiction. Leaving them on will help them as well. > How many spin hours can they be expected to >last? According to the docs on my WREN-IV, 100,000 continuous hours. The specs for your drive, obviously, may be different. >Lastly, is it feasible to create a "sleep" mode for your computer >in which the hard drive spins down but the CPU stays on to keep warm? I suspect that the portable does this, to conserve power. The SCSI spec seems to implement two commands, Start and Stop, that could be used for this purpose, but since the mac doesn't send a Start on boot, this may not be a feasible solution (I'm a bit fuzzy on this part) -- Matthew T. Russotto russotto@eng.umd.edu russotto@wam.umd.edu .sig under construction, like the rest of this campus.
Paul.Heller@f421.n109.z1.fidonet.org (Paul Heller) (02/16/91)
WC> The most cogent reason I've seen for turning off the mac is the possib
WC> of excessive wear on the spinning hard drive. How well engineered are
WC> hard drives in that regard? How many spin hours can they be expected
WC> last? Lastly, is it feasible to create a "sleep" mode for your comput
WC> in which the hard drive spins down but the CPU stays on to keep warm?
There is a school of thought that believes that hard drives last longer
if you leave them running around the clock, for several reasons:
a) there's no temperature cycling. Hard drives generate a fair
amount of heat, and daily heating up & cooling down is believed
by some to contribute to wear and tear. Also, heating & cooling
may, so goes the theory, cause air to be breathed in & out,
possibly carrying contaminants.
b) Electrical surges during startup are less frequent. This applies
to the rest of the computer as well.
c) In designs where the read/write heads come to rest on the disk
surfaces, keeping the drive spinning reduces the chance that the
heads & media surface will do nasty things to each other while
at rest (or while bumped while at rest.
Personally, I'm inclined to believe that the period when a computer is
powered up from a cold start is a relatively stressful time for the
components -- all of them, not just the hard drive -- and that the
strategy of keeping the equipment running around the clock has
something going for it. When a computer or hard disk fails, more often
than not it's when it's first turned on ... the downside of this
strategy is that power cost isn't insignificant, and leaving a computer
running that draws, say, 150 watts, for 16 unnecessary hours a day
might increase your power bill by $10 or $11 per month, or $120 or so
per year.
As far as the bearings in the drives are concerned, the ones produced
during the past few years all seem to have very long lives, and I doubt
that having them spin 24 hours/day is going to cause them to fail
prematurely because the bearings wear out.
This is probably one of those can't-win situations. My advice: buy
good-quality components and keep your fingers crossed.
--
Paul Heller, Paul.Heller@f421.n109.z1.fidonet.org
via The Black Cat's Shack's FidoNet<->Usenet Gateway
blkcat.fidonet.org and Fidonet 1:109/401jp48+@andrew.cmu.edu (Jonathan Pace) (02/18/91)
I won't argue the merits of turning the drive off and on excessively, except to say that the actual drive mechanism is sealed air-tight and booting up and down cannot draw air into it. What I can say is that there is a way to power your HD up and down without shutting off the Mac. I have a control panel device called SCSI Saver that was written and distributed to the public domain. You throw it in the system folder and then set the number of minutes of non-disk access until the drive is to be spun down. The drive will automatically come up to speed when access is requested (but it takes about 20 seconds more). I'll be glad to mail it to anyone who wants a copy. Jon Pace Carnegie Mellon Univ.
fadushin@rodan.acs.syr.edu (Fred Dushin) (02/18/91)
In article <8bjkcly00WB64_r1Mx@andrew.cmu.edu> jp48+@andrew.cmu.edu (Jonathan Pace) writes: > What I can say is that there is a way to power your HD up and down without >shutting off the Mac. I have a control panel device called SCSI Saver that >was written and distributed to the public domain. You throw it in the system >folder and then set the number of minutes of non-disk access until the drive >is to be spun down. The drive will automatically come up to speed when access >is requested (but it takes about 20 seconds more). Could you tell us more about your configuration? The reason I ask is that I am running Siverlining, and I am wondering whether such cdevs can potentially interfere with such disk partitioning/ management software? Do you know of any horror stories? Fred Dushin Syracuse University, Syracuse, NY Internet: Bitnet: fadushin@rodan.acs.syr.edu fadushin@sunrise.bitnet (FYI, RODAN is a Sun4 running SunOS Release 4.1_PSR_A.)
jp48+@andrew.cmu.edu (Jonathan Pace) (02/18/91)
Can SCSI Saver interfere with partitioning software?? Good question. I've never had any problems with it, and I've never had any of my friends attribute anything to it. My setup. One original Apple internal 40 Mb drive, one external 180 Mb drive partitioned into a 40 Mb and a 140 Mb. The cdev works by checking for SCSI devices on the chain. You can select which, if any, spin down. It will spin down an entire drive, so you can't take down just partitions (most people could guess this already). The concept doesn't seem too complicated to me. Look for a given period of inactivity, send the drive a "sleep" command after it, and then a wake-up call if anybody needs it. I believe these are Macintosh "standard" commands, so I can't imagine a Mac drive not responding to them. If I recieve any feedback pro or con when the people who have asked for it start using it I'll post here. Jon Pace p.s. - How does everyone quote a message? I never learned how. >>>
aslakson@cs.umn.edu (Brian Aslakson) (02/19/91)
Paul.Heller@f421.n109.z1.fidonet.org (Paul Heller) writes: > c) In designs where the read/write heads come to rest on the disk > surfaces, keeping the drive spinning reduces the chance that the > heads & media surface will do nasty things to each other while > at rest (or while bumped while at rest. Worse would be if bumped while spinning, yes? I've seen some very interesting gouges... -- Brian Aslakson aslakson@cs.umn.edu mac-admin@cs.umn.edu <-= Macintosh related