OK to leave PC On All The Time? 2

[peterv3]

I have been told that it is OK to leave the PC on all the time as shutting it down and bringing it back up again only causes damage to the hard drive? Is this true? I have been leaving it on mostly because I have Virus scans scheduled for 3:00 am or earlier when I am not using the PC. Any feed back would be greatly appreciated.


Peter Vaicels
Flanders NJ USA

 

[cadmancan]

It is my opinion that it is not good to leave your computer on at all times. Working for an ISP, teching for some time, having parents who were property claims adjustors, IT'ing for a company of 150, have taught me well.
First your older OS's were not designed to be left on all the time. With the newer ones it may be OK, but your shortening the longevity of your box.

You are suceptible to power spikes and dips (because of no surge supressors or cheap ones).

Linux boxes and win 2k server boxes are meant to be left on for understandable reasons, but not HOME users.

If you live in California, computers are a culprit, albeit notthe main reason why there is a crisis. Think if just 2 out of 5 people leave their computer on because they are under the false impression that it is bad for the system, times that with printers, even monitors in sleep mode. The numbers are staggering.

Then I have seen several insurance claims of boxes, monitors going up in smoke, sometimes even taking a whole house out.

Then there is longevity. All though it is hard to track, you are limiting your parts to failure, overheating, dust and many other things.

Maybe it is just me, but it suprises me that so many people hold to the opinion of keeping the system on. To each their own. But if you do so they'e are many issues to consider first. Peace

 

[cadmancan]

Another note. It is incorrect to assume that it is hard on the switch. You will have to replace your hardware (hard drive, video card), by leaving it on way before you will have to replace a switch by deciding to leave it off.

 

[drosenkranz]

Hello,

The most "wear and tear" on computer (electrical) components is heat. Shutting down and restarting later allows the PC to cool off - and subsequently, reheat. This will eventually take its toll on the components and/or wiring - but restarts can not be totally eliminated either.

The second leading cause of damage are "spikes" coming over the electrical line. The potential for a lightening strike from the plug or via the phone line is an obvious reason to put a good surge protector on your system. Even a strike in the vicinity of your house or telephone lines can ruin equipment.

Running an appliance (such as a toaster) on the same circuit as your computer in your house will produce a smaller momentary spike - when turning the appliance on and off as well. Although this spike is miniscule in comparison to lightening, these changes in electrical current flow will also eventually stress your electronics too.

Think of it this way - your computer offers "resistance" (in ohms) that the electrical "pressure" (voltage) must overcome in order for current (amps) to flow though the computer and back out the other prong on your plug. This amount of power that your computer's combined circuitry uses is measured in "watts" (power consumption).
When the voltage changes (albeit momentarily), the "pressure" (voltage) on your PC's electrical components is also fluctuating. This causes wear and tear on the components in your PC - even the wires. Ever wonder why a lightening strike can blow a phone line off of the telephone pole? Too much pressure. Ever wonder why your car's battery has those thick wires bolted onto the terminals? Pressure.

A computer operates internally in milliamps (thousandths of an amp). A tenth of one amp can stop the human heart . Your car starts up at 500 amps or more - frequently advertised as the "cold cranking amps" of your battery - until you let go of the key.

Now don't lose any sleep worrying about it, just make sure you plug your PC into its own circuit from the breaker box - or at least use a circuit that doesn't have any major appliances running on it. See... what you don't know CAN hurt you.

Dave


The 2nd mouse gets the cheese.

 

[RICHINMINN]

I agree with edfair, flashmedia, drosendranz, and numerous others who have posted here.

I've been using PCs since the mid 70's, and have been building/supporting them since the early 80's. Probably the biggest cause of failure in PCs is heat. How can you minimize the heat that's generated? Shut the system down when you're not going to be using for some length of time, say 4-8 hours or more. Yes, there is a wear cost associated with booting a system, but there is also a wear cost associated with leaving a system on all the time.

In the early days of PCs, when a power supply was in the 63.5-135 watt range, the power spike to the power supply when booting up could indeed "fry" the PS, so many "knowledgeable" computer buffs determined that they should leave their systems on continuously to prevent the chance of this happening. Current systems, though, with power supplies in the 300-350 watt (and higher) range can absorb this without too much complaint. Other components are designed to better deal with the "trauma" of starting up. (Beware though, because many of today's low-cost systems offer power supplies in the 160-180 watt range, which is JUST enough to power the components designed into the system, without the addition of any other components (CD/R-RWs, DVDs, etc.), or to provide the "overhead" to be able to absorb a power spike.)

Similarly, old MFM hard drives originally had a MTBF (Mean Time Between Failures) of 10,000 hours or so, while IDE and SCSI hard drives now have a MTBF of 100,000-300,000 hours. If left running continuously, this would amount to 11-33 years. Why then do most hard drive manufacturers guarantee their products for only one year, or two, or three at the most? (A year is 8760 hours.)

If you DO choose to leave a PC running for extended periods of time, be sure to change the Power Management settings in the BIOS to power down the hard drive after some reasonably short period of time, 15-30 minutes, say, because if the system needs to access the drive, it'll spin it up again to read/write whatever it needs. Also, be sure to set your monitor to remove voltage from the guns (rather than just clearing the screen, as a screen blanker does). Most newer monitors have this capability built right into them.

Also, servers that are left powered up for weeks and months on end are usually in a temperature-controlled environment. Is your home or office maintained at a constant 68 (or lower) degrees, with emergency procedures in place if the temperature rises above this?

The most commonly replaced component in PCs (in my experience) is the modem. And a modem failure is most likely caused by a lightning strike somewhere in the vicinity (though not necessarily close). Every PC I build is delivered with a surge suppressor of at least 3000 joules. (A joule is the measure of "clamping power".) Many of the "surge suppressors" sold in computer stores or elsewhere offer 300-500 joules, which is better than no protection, but perhaps gives a false sense of security that a person's computer is protected. Be sure to get a surge suppressor that also has protection for a phone line as well as a TV cable, to prevent damage to the internal modem or the external cable/DSL modem.


Keeping computers running for over 20 years... (though not necessarily running continuously...)

Rich (in Minn.)