Sleep (or on/off) bad for HD's?

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nesika41

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Someone said that, even for modern HD's, spinups and downs reduced their lifespan, and, therefore, he set his sleep function to never, and left his computer on 24/7.

Any test results supporting this? (My imac600 HD [Maxtor] failed after about 3 years, and I had it set to sleep after 15 minutes.)
 
My machines run 24/7, drives set to never sleep. Three drives, two are Maxtors at least 6 years old. No problems.
 
bobw: But it's the other side of the coin that I'm wondering about: would they still be running if they'd been put to sleep several times a day?

From what I can find so far through googling, heat is the biggest enemy of HD's, and a spinning HD generates more heat than an idle one. So, is there something "bad" about spinups and downs? If so, what?
 
I doubt it. My opinion (just mine) is that setting to sleep would lower the life span.

I had my original drive go bad after less than two years and I had that set to sleep after 30 minutes. Since then, I don't let them sleep.
 
Thanks to you, bob, I finally found the right google search term:

leave hard drive running 24/7?

After MUCH reading of the results (I won’t bore people with 12-15 links), the consensus seems to me that--as far as your system goes--leaving the computer on 24/7, allowing monitor to sleep as necessary, would result in longer life, perhaps significantly longer, as you suggest. Course, that doesn’t address the unnecessary energy consumption.

Several imaginative answers to the energy consumption dilemma. Your computer probably draws +/- 100 watts, so start replacing those 100 watt incandecents with CFLs; much cheaper than a new HD.

And, I really like this one: go here

http://www.distributedcomputing.info/projects.html

and find a good cause; then, that “idle” but unasleep computer can be doing good work.

The only downside is that now there may develop a debate about whether distributed computing is bad for your computer.
 
This is interesting since the spin-up will put a bit more stress on the drive motor and likely reduce its life in some ways. However, every drive I have ever had die on me it was never the motor that died. Either the head crashed or a bearing failed both of which are heat and (umm...) acceleration related problems.

Particularly with modern drives that have self parking heads, a few seconds after the last read or write the drive is effectively in the "off" configuration, save for the spinning of the platters.

So I would say hibernate is the better choice since it reduces heat whihc is always bad.

But with a caveat, my brother works with large disk arrays, things with hundreds of disks. And he said that whenever they power one of the things down there will always be one or two disks that don't come back up. This is because they run at full bore for a long time and are always hot, then when you let them cool down and try to bring them back that is when the weak ons go. It is just like how a light bulb is most likely to burn out when you are turning it on.

So back up your data and do whatever is most convenient for you.
 
bobw said:
My machines run 24/7, drives set to never sleep. Three drives, two are Maxtors at least 6 years old. No problems.
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As an elect. tech of about 40 odd years, with a minor in electronic design on my masters, let me say that turn on transients do the most damage to most equipment: light bulbs, 60" HDTVs, computers. The primary effect is an AC voltage spike at turn-on. However, once the computer is up and running, the main power supply is regulated, and there should be little or no voltage transient as a module down the line comes on, say a hard drive. But, I still feel that turn on is the worst thing you can do to a piece of electronic equipment, EXCEPT for--leaving it on long enough that the heat does more damage than the turn on. Where that line is, is the question. I have (and am writing this on) a nearly 10 year old PTower Pro. The original hard drive failed after about 4 years. I didn't use sleep then. I replaced it, added a new internal drive for back-up, and added a third, 12 year old drive for secondary back-up. Then I set sleep to 30 minutes. I think I now have it set to 15 minutes. The way I use my machine, the drives frequently sleep for hours before re-awakening. I also shut the machine down totally, and disconnect the main power from it when through for the day. We have lived in areas where power failures are endemic.

Turn-on transients from the power company when the crews are reconnecting main lines can be 1000 volts to 1500 volts. Short lived transients, but can do a lot of damage. So, I disconnect from the main 120 AC supply, when the machine is not going to be working.

If your drives are constantly re-awakening and going to sleep, that probably does more damage than constant run.

If they operate like mine, sleep probably saves damage.

There used to be a general rule--The 6 hour rule, if a device is going to be used again within 6 hours, it is safer and less damaging to leave it on and un-used, than to turn it off and then turn it back on 5 or 6 hours later. Longer than 6 hours, better to shut it off and then turn it back on. Not hard and fast, but in general true. Today, 4 hours might be a better figure. I follow the 4-6 hour rule with most of my electronic equipment, from test equipment to 65" inch HDTV.

The caveat is the power company. If the main lines go down, the reconnection turn-on transient can destroy not only delicate electronic equipment, but also refrigerators, AC compressors and blower motors, and more. Disconnect in case of power outages.
 
bob: Thanks for the lengthy explanation. [Oopps, sorry: thanks RGM!]

So, in the case of my girlfriend, who (99% of the time) uses her computer twice a day, briefly, morning and evening to check email, she would be advised to put it to sleep after each use. My case, since I use it off and on all day, I should only put it to sleep when I go to bed.

One side question: I've seen a lot of people express concern, as you do, about power surges. Some have suggested that a good battery backup, like APC, will stop surges, others say no. Also, some say you should replace the APC every coupla years, as they "lose it". Your thoughts?
 
My vote: After you turn the computer on leave the hard drive(s) running until you go to bed. Don't let the computer go to sleep until then, only the display. Computer sleep shuts down the HD also. OWC (Other World Computing) advised me not to be turning the HD on and off during the day. In addition to bearing stress, when the HD is shut down, the read/write head is allowed to land on an unused part of the disk when it spins down, causing head wear. During startup, the head rides the disk until air pressure builds up from aerodynamic forces and "floats" the head. Most drives are rated for about 50,000 start/stop cycles before 50% failure probability. That means a few can fail long before that, a few will last a lot longer. Why play Russian roulette? Limit start/stop cycles, the drive will likely live longer, you'll have less chance to lose data.
 
Egads. After all this discussion, I see why the hard disk of my PowerBook failed. Constant on and off sleeping and such, combined with hardcore Final Cut editing and Halo creating heat: ye gods!

Is anybody actually working on drive reliability and data integrity, rather than mere capacity?
 
Yup, same with my imac600, whose HD failed after about 2.5 years. Compulsive email checker that I am, and a fitful sleeper, mean that the imac probably spun down/up 10-15 times a day, as I kept it set to sleep after 15 minutes.
 
nesika41 said:
Yup, same with my imac600, whose HD failed after about 2.5 years. Compulsive email checker that I am, and a fitful sleeper, mean that the imac probably spun down/up 10-15 times a day, as I kept it set to sleep after 15 minutes.
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I bought an iMac 600 on eBay, and the hard drive had failed - not from spin downs, but from heat buildup. Those machines were the first (I think) iMacs to be fan-less, so they must have been still a bit buggy.
 
At work I have only the displays go to black / protected screensaver after a few minutes of inactivity. Hard drives never, as well since I need to be able to connect to them whenever I need to, and use the main Mac also as a server.

At home ... if the iMac G5 that I have with the 400 GB hard drive taken from an XServe RAID into it was more quiet in use, I wouldn't put it to sleep. But the noise is driving me insane .... Cube is so far in sleep for most of the time, but when I'll have replaced the 20 GB HD with a 120 or 100 GB one, it'll have Server, and Remote Desktop to it 24 7 ... at least that isn't too loud to leave on. If only ARD would allow waking for admin access so wouldn't need to get an ethernet cable from the other end of the house for it ... :)
 
nesika41 said:
bob: Thanks for the lengthy explanation. [Oopps, sorry: thanks RGM!]

So, in the case of my girlfriend, who (99% of the time) uses her computer twice a day, briefly, morning and evening to check email, she would be advised to put it to sleep after each use. My case, since I use it off and on all day, I should only put it to sleep when I go to bed.

One side question: I've seen a lot of people express concern, as you do, about power surges. Some have suggested that a good battery backup, like APC, will stop surges, others say no. Also, some say you should replace the APC every coupla years, as they "lose it". Your thoughts?
Click to expand...

Hi nesika41

I think in another thread I said something like depending on the design, a battery-back-up might protect from the electric co. turn on transients, or lightning strike transients. I can conceive of a design of battery back-up that would do this, whether anyone actually produces one that will, that is something I don't know. It would have to sense the overvoltage spike and switch to battery op. in far less than one half a cycle of the frequency (60 Hz), so in way less than 1 / 120 th of a second. I remember seeing ads that claimed switchover in less than 1 / 1000 th of a second. That might be enough to do the job, but it would be cutting it close. A battery back-up that ran the computer full time from the batteries and kept them recharged at the same time might do it, but designing this concept might be a real problem.

So, honestly, I don't know. I don't have one, I use an old constant voltage transformer. It is designed to keep slower voltage changes from getting thru to the equipment. It clamps the output AC to the range of about 95 or 100 volts to 130 volts, and protects from brown-outs and smaller slower overvolt spikes. It is a transformer(thus inductor) capacitor resonant circuit that really likes to produce 120 volts at 60 Hz, and will do everything it can to keep on producing 120 volts at 60 Hz. I also have 130 volt suppressors on it and on the surge protector it is plugged into. I don't use my computer constantly, so this works for me. The const. volt. transformer sucks a lot of power just for its two components, the inductor/transformer and the capacitor--about 250-300 Watts. It keeps my feet warm in the cold weather. Probably not the best solution for most people.

Most surgeistors (the device that is supposed to shunt or conduct away overvoltage spikes) in many surge protectors are rated at 200 or 250 volts. That lets in a little more voltage before protection than I want. So, I bought some 130 volt rated devices and soldered them in my surge protectors and in the constant voltage transformer. Then, if I hear thunder or if the power goes out, I turn the system off at the constant voltage transformer, which isolates the system completely (the way that I have wired my unit's switch) from the electric lines.

Good luck. rgm
 
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