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Is it wise to... (prob a daft question)

Discussion in 'General Hardware' started by Dan2312, Oct 15, 2009.

  1. Dan2312

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    To turn off your PC and wireles modem at the mains socket?

    ive heard mixed things about damaging components and that its bad for a wireless modem in general.

    Cheers.
     
  2. Soylent Joe

    Soylent Joe New Member

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    You mean like pulling the plugs from the wall?
     
  3. aCid888*

    aCid888* New Member

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    This is a strange question.......

    If you unplug it from the wall while its on it isn't very good.....on that note if you do it when they are turned off it wont do any damage at all.

    That's about the best way I can answer this vague question. :)
     
  4. Asylum

    Asylum

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    A correct anwser to a vague question... aCid.
    As long as you completely shut the computer down before unplugging the power there shouldnt be any problem at all.
     
  5. Mussels

    Mussels Moderprator Staff Member

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    computers still draw power when "off" if left plugged in at the wall.

    if you are leaving them in an "off" state for some time, then i do suggest unplugging them from the wall.


    i do NOT suggest unplugging them at the wall, while they are on. They dont like that.
     
  6. Dan2312

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    ah right, i noticed that mine is still drawing power from the wall, i was bothered that it may affect the bios etc.
     
  7. Mussels

    Mussels Moderprator Staff Member

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    nope, thats what the CR2032 3V battery is for :) (also called CMOS battery, BIOS battery, etc)
     
  8. _Zod_ New Member

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    Like all modern electronics these days, nothing is ever truly off anymore. The draw when the PC is off is to keep the CMOS settings intact. IF you remove power it will run purely off the 3.3v battery thus hastening the batteries demise. The downside to leaving it drawing power is $ and if you're paranoid, the contents of memory stay longer thus snoop-able by the man.

    Now if you were an eco nut, you would replace the 3.3v with a rechargeable one and a small solar charger to charge it (lol)
     
  9. Mussels

    Mussels Moderprator Staff Member

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    those batteries can last for years in a PC, without power. 5-10 years shelf life sitting in a motherboard is completely within reason - when they're sitting in the motherboard box, they're keeping the CMOS running already anyway.
     
  10. FordGT90Concept

    FordGT90Concept "I go fast!1!11!1!"

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    ...to convert AC to DC and DC is needed to keep that CMOS battery charged. It's only a few watts but it adds up.


    Unless you got a FUBAR motherboard. I had one that killed a battery every 10-14 days. :( MSI replaced twice (first RMA made the battery last a few months, second fixed it). :)


    I've left computers unplugged for probably pretty close to 7 years. The clock was off (as expected having not been resync'd in that period) but the CMOS data remained intact.


    All CMOS batteries (CR2032 is extremely common) are rechargeable.


    Pulling the plug out of the wall when the computer isn't prepared to shutdown disallows the shutdown process to happen (save settings, stop HDD writes, etc.). It isn't necessarily hard on the components but you run the risk of corrupting data.
     
    Last edited: Oct 16, 2009
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  11. Mussels

    Mussels Moderprator Staff Member

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    ford: its not that at all. its related to the 5v USB standby rail (5VSB) - the systems have a small amount of power go through for PS2 and USB devices, so that the system can power up from standby when they're pressed.


    if the CMOS system used " a few watts" (as opposed to a few milliwatts) we'd either be replacing those batteries every 3 months, or we'd be using them to run our cars, since they'd hold so much power.
     
  12. FordGT90Concept

    FordGT90Concept "I go fast!1!11!1!"

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    Standby != shutdown. The memory is completely powered up as is any "wake on" buses. Regardless, you're still wasting power converting AC to DC so long as the computer is plugged in (such is the case with all transformers).


    CMOS is measured in milliwatts, getting those milliwatts to the CMOS takes watts (again, transformer).


    There are "eco power strips" that cut power to anything using less than x watts. That's the best way to save electricity with anything that uses an AC -> DC transformer.
     
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  13. Mussels

    Mussels Moderprator Staff Member

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    you're misinterpreting my use of the word standby.

    Televisions have the same systems these days - you no longer have to turn them on and off via cutting and restoring mains current to them, they have a 'soft' switch that wakes them from a standby mode.

    its the difference between AT and ATX PC's - one has the current 'cut' and restored via actually cutting the circuit, while the other never truly gets cut off - everything just turns off, leaving the connection active.

    as for 5VSB, google it or something. its rail on the PSU, and thats what draws the power when the sytem is 'off' - you've never set your PC to turn on via USB or PS2 keyboard, from an "off" (not S1/S3 sleep) state? never seen a PC that could charge/power USB devices when off? never noticed all the LED lights on modern motherboards, or the LED activity lights that remain on your LAN ports?

    power is drawn while systems are off, but the CMOS is but a tiny, tiny fraction of it.



    P.S
    CR2032 batteries used in PC's are not rechargeable.
    http://en.wikipedia.org/wiki/Button_cell

    they're also 3V, not 3.3V like some people are saying.
     
    Last edited: Oct 16, 2009
  14. FordGT90Concept

    FordGT90Concept "I go fast!1!11!1!"

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    ATX compatible power supplies/operating systems allow for enabling/disabling "wake on" events. My computers, for instance, have everything disabled except power switch. I don't put any computer in stand by, ever. Moving the mouse, pushing a key, etc. has no effect on it.
     
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  15. Mussels

    Mussels Moderprator Staff Member

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    mine all have BIOS options to wake from an off state via wake up events.

    They tend to only work after the PC has been turned on and shut off once, but they're still there.


    My intention was only to clear up the issue of what is using the power when a PC is 'off' - even if you disable those features from waking the PC, they will still use power.
     
  16. FordGT90Concept

    FordGT90Concept "I go fast!1!11!1!"

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    Only if the motherboard is designed to do so. ATX specification allows the motherboard to control the power state to some extent (power on, standby, power off). In AT, the power switch was physically connected to the power supply. ATX places the motherboard in between.

    Some motherboards always have USB powered in a powered off state, some don't.
     
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  17. Mussels

    Mussels Moderprator Staff Member

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    when you find a motherboard that doesnt use the 5VSB rail to power ANYTHING on the motherboard, i'll believe you.

    i've been testing hundreds over the years, since i got my first ATX PSU (and wondered why the lights still blinked), and been doing more and more thorough testing as i got better tools (namely, a wall socket power meter)
     
  18. FordGT90Concept

    FordGT90Concept "I go fast!1!11!1!"

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    All you have to do is look if the mouse optics are lit when the computer is off. I only encountered one that does.
     
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  19. Mussels

    Mussels Moderprator Staff Member

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    quite often theres a motherboard jumper for USB, to turn that on or off.
    PS2 its usually on (after the first boot, as i mentioned before)


    even when the power doesnt get put to external devices, it still gets used internally (LED's, LAN port LED's, the little switch that wakes the system up when you hit the button, the IC that controls what devices allow wakeup (WOL, WOM, wake up events from mouse/keyboard/USB/PS2)

    i'm just trying to make my point clear, that no matter what you do, change, or set - ATX systems will always draw power.

    i'm not sure the point you're trying to make, you're making statements "i dont use sleep states" "my mouse doesnt glow" - but i'm not seeing the point you're trying to make
     
  20. FordGT90Concept

    FordGT90Concept "I go fast!1!11!1!"

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    My KVM is PS/2 and when all connected computers are off, it no longer has power (it is entirely powered by PS/2).


    LAN is another one that is motherboard dependant. Some keep the NIC powered up and some don't.


    Yes, ATX will always draw power in AC -> DC conversion as well as voltage to the power switch. How many stops it makes between here and there is up to the motherboard manufacturer.
     
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  21. Mussels

    Mussels Moderprator Staff Member

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    alright, well your system doesnt use that for power then. I bet if you measured it at a wall, your PC would use about 3-4W when off.



    I did tests on mine, disabling the 5VSB for USB and PS2 (the board had jumpers) cut the "off" wattage from about 9W to 4W (and about 6W in S3 sleep states)


    as for the comments earlier about the power being used by the CMOS battery, a few statements.

    the CMOS battery can maintain these settings for years on a shelf, so whatever power draw that is must be very low compared to how much the battery holds.

    If that draw is several watts (or joules per second) the the battery must have a large watt hour capacity, or be rechargeable.

    the wiki link i showed earlier, proves that they arent rechargeable.

    [​IMG]

    This image proves that they have a low power capacity (230maH for a known quality brand)

    summary: there is no way in hell the power drawn from a PC at the wall, is related to the CMOS battery and its functions.
     
  22. FordGT90Concept

    FordGT90Concept "I go fast!1!11!1!"

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  23. Mussels

    Mussels Moderprator Staff Member

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    but they wont recharge in a PC.
    if PC's recharged them, putting a non rechargeable in they'd explode/leak, whatever.

    again, you're finding some tiny wee little thing (the wiki link stated they exist, but they're rarely used due to them lasting a lot less) and not actually providing any counters to what i'm saying.
     
  24. FordGT90Concept

    FordGT90Concept "I go fast!1!11!1!"

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    ...

    [​IMG]


    It keeps it charged by not using it.


    CMOS can operate from approximately 3.5v to 1.5v (if memory serves). Any lower than that and you can expect errors.
     
    Last edited: Oct 16, 2009
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  25. ShiBDiB

    ShiBDiB

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    so a mod and a user threadjacked... cool
     

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