how big should my power supply be?

Discussion in 'Computer Information' started by tempus fugit, Feb 22, 2004.

  1. tempus fugit

    tempus fugit Guest

    Hey all;

    My computer has been acting weird lately (random reboots, random shutdowns,
    reliablity issues, etc), and I'm starting to wonder of my PS is on it's way

    I'm currently using a 300W PS (don't remember the brand), on my Windows 98SE
    with Athlon 950, ECS K7S5A mobo, 384 megs PC133 RAM, DVD rom, CDRW, 2
    soundcards, ATI 128 Meg video, and 2 hard drives (1 is 5400 RPM, the other
    7200). I think that covers it. Can anyone advise me or point me to a site
    that outlines the typical current requirements of these devices so I can
    figure out if I should go to a bigger power supply?

    tempus fugit, Feb 22, 2004
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  2. tempus fugit

    Drifter Guest

    Well, you don't give a lot of specifics to work with but some general
    rule-of-thumb guidelines...

    O/S doesn't matter in this case.
    Athlon 950 -up to 50 watts
    ECS K7S5A- 20-30 watts
    384 MB RAM 20-30 watts
    DVD ROM- 20-25 watts
    CD-RW- 20-25 watts
    Sound card 7-10 watts (you say you have 2 so 14-20 watts)
    Hard Drive(s) 15 watts (x2- 30 watts)
    Video card Hard to guess without the specific model, but we'll
    say 30-50 watts.

    So running on the higher estimate you need roughly 260 watts. Now add
    in roughly 10% to cover the internal loss when the power supply and
    computer warm up and you are at about 286 watts.

    In addition it has become widely known that far too many brands of
    power supply provide as much as 15% less power than their sticker
    "rating" claims (that could put your power supply down as low as 255

    So in summary, yes I would say you probably need a larger power supply
    (say 350-400 watt). Make sure you buy one with a solid reputation
    like the Antec "True Power" series. Do the research BEFORE you waste
    your money.

    "I've been here, I've been there..."
    Drifter, Feb 22, 2004
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  3. tempus fugit

    DeMoN LaG Guest

    Complete crap. I've run a Duron 1.2 with 2 IDE drives (5400 and 7200 RPM),
    an IDE RAID controller, a SCSI controller, 2 5400 RPM SCSI drives, and 512
    megs of RAM on a 300w supply with no issues at all. The main question is
    the quality of the drive. Get a high quality Antec or Enermax, or Sparkle
    power supply, and you can get by with a lower rating. If you buy a cheap
    $15 power supply, then you'll get crap output.

    AIM: FrznFoodClerk
    email: [email protected] (_ = m)
    website: under construction
    Need a technician in the south Jersey area?
    email/IM for rates/services
    DeMoN LaG, Feb 22, 2004
  4. tempus fugit

    Thor Guest

    2 optical drives (both burners)
    80GB 7200 HDD
    512MB RAM
    Athlon 2100+ T-Bred
    extra USB 2.0 card w/5 ports
    A7N8X Mobo
    Geforce 4 Ti 4800
    5 case fans
    all on a PC Power & Cooling turbo 350 power supply. And it barely gets warm.
    Thor, Feb 22, 2004
  5. tempus fugit

    Drifter Guest

    You post here a lot and you give a lot of advice, but jeez can you
    dump the damn attitude you've picked up lately. You can say you
    disagree with me without being a jerk about it.

    "I've been here, I've been there..."
    Drifter, Feb 22, 2004
  6. tempus fugit

    Michael-NC Guest


    Athlon 1GHz, 512MB ram, 2- 7200 HDDs, 52X Burner, NIC, Cordless Mouse/KB,
    8MB Intel I740 Video on a 250 Watt PS from The units been
    running trouble free, 24/7 for well over a year. Quality counts.
    Michael-NC, Feb 22, 2004
  7. tempus fugit

    Drifter Guest

    Numbers guys, numbers.
    Abit BH7 Mobo (Incl NIC and Audio card): 50 watts
    Intel P4 2.4b CPU: 75 watts
    1gb RAM 30 Watts
    ATI Radeon 9700 Pro Vid Card: 30 watts
    4 IDE HDD (15ea X 4) 45 watts
    IDE RAID card 07 watts
    Hercules Sound card 09 watts
    CD-ROM drive 25 watts
    DVD-RW Drive 25 watts
    FDD 05 watts
    Vid Capture Card: 15 watts
    Case Fans (4 each X4) 16 watts
    Vantec Tornado Fan 09 watts

    Total: 341 watts

    Now according to the numbers I obtained -from the manufacturers- I
    should have been able to run my system with a 350 watt power supply.
    Guess what, didn't work even with a TruePower supply. Found out later
    that the Vid Card was actually pulling about 45 watts and the RAM was
    pulling about 40 watts for a total of 366 watts. Had to jump up to a
    400 watt before everything settled down and played nice.

    My point is that the numbers I gave the OP were an estimate based on
    his somewhat sketchy information (very few model numbers, etc) and
    based on that estimate he could be running close to, or over, the wire
    ESPECIALLY if he has a cheap power supply.

    "I've been here, I've been there..."
    Drifter, Feb 22, 2004
  8. Dear: Tempus,
    I don't think your Power supley is not powerful enough, I am using WIndows 98SE
    two and know that the operating system can not handel A DVD ROM and 384 PC RAM.
    It could handel a CD-RW, but not a DVD-ROM(DVD-ROM's need a lot of power and
    speed:).Two hardrives might be a little hard to process(Even know it donsen't
    show) Harddrives on Windows 98SE must be under 20Ghz.If your computer is
    processing under 1.5Ghz it would be good to Take the DVD-ROM out of the
    computer.It is possable that your PC could not give enough power, but that's
    preedy rare.
    Travis Nowicki, Feb 22, 2004
  9. tempus fugit

    Wizard Guest

    I gave him the same friendly advice 6 months ago and he didn't take it
    so I just kill filed him and have not missed anything significant that I
    can tell.
    Wizard, Feb 22, 2004
  10. tempus fugit

    DeMoN LaG Guest

    .... I am really not certain where to start debunking this. 9x can easily
    handle a DVD, multiple hard drives (really you could have 15 hard drives
    and 9x won't care), and Windows 9x can run with up to 1 GB of RAM with the
    right little trick, otherwise the max is 512. It is not at all rare for a
    PC to not get enough power. I had a customer just last week who bought a
    custom system with an Athlon, DVD, CDRW, 2 HDDs, extra NIC, sound, and a
    GF4 for video that used a really cheap (I'd put it in the $10 ballpark)
    power supply. Sure, it was 400w, but the voltages coming off of it were:
    3.3: 2.9
    5: 5.6
    12: 12.89
    VCore: 1.85 (at the lowest possible setting in the BIOS of 1.65)

    Machine crashed, locked up, worked like poop. Replaced it with an Antec
    400w unit, voltages came back to spec, machine worked like a charm.

    AIM: FrznFoodClerk
    email: [email protected] (_ = m)
    website: under construction
    Need a technician in the south Jersey area?
    email/IM for rates/services
    DeMoN LaG, Feb 22, 2004
  11. tempus fugit

    tempus fugit Guest

    You gave ME friendly advice 6 months ago? I don't think so... at least I
    don't remember asking this question (this is the first time I've had
    problems like this).
    tempus fugit, Feb 23, 2004
  12. tempus fugit

    tempus fugit Guest

    I am thinking that I need a new PS at any rate, and figured I might as well
    go a little higher if it would help. I'm also having problems with burning
    CDs, system lockups, monitor display screwups, etc. that seem to be resolved
    for a while after a reboot.

    I know it's hard to say for sure with all the different components involved,
    but do these things sound like PS problems?

    Thanks to all who posted.
    tempus fugit, Feb 23, 2004
  13. tempus fugit

    Drifter Guest

    He was referring to DeMoN.

    "I've been here, I've been there..."
    Drifter, Feb 23, 2004
  14. tempus fugit

    Michael-NC Guest

    It wouldn't hurt to buy a quality 450 watt power supply and swap it out. If
    that don't do it, you still have a new, quality 450 watt power supply for
    your next upgrade.
    Michael-NC, Feb 23, 2004
  15. tempus fugit

    tempus fugit Guest

    Good advice, to be sure. I was kind of thinking along those lines (although
    not quite as high as 450)

    tempus fugit, Feb 23, 2004
  16. tempus fugit

    tempus fugit Guest

    My mistake. Sorry.

    tempus fugit, Feb 23, 2004
  17. tempus fugit

    Michael-NC Guest

    Only reason I suggest a 450 is to "future proof" the component for another
    Michael-NC, Feb 23, 2004
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