Results 1 to 11 of 11

Thread: Understanding Power Supplies.........

  1. #1
    Member
    Join Date
    Nov 2003
    Location
    Wales
    Posts
    174
    Thanks
    0
    Thanked
    0 times in 0 posts

    Lightbulb Understanding Power Supplies.........

    Hi all,

    I am getting quite a bit of fluxuation on my 12V line off my QTEC 550W. I am trying to understand what devices run off a 12V connector.
    Am I correct in assuming Hard Drives, CD/DVD Drives, 4pin Case Fans all take juice off the 12V ? (If I have missed something please let me know).
    So what devices run off the 5V supply, PCI cards etc?
    Also, I am trying to improve my 12V when overclocking (as it dips to 11.74 when @ full throttle ), do you think by changing to 3pin case fans it would help?? Any input appreciated.
    C2Q6600 @ 3.15GHz
    ThermalTake MiniType90
    EVGA 680SLI
    4GB OCZ Reaper 1066MHz @ 1000 4,4,4,15
    EVGA 8800GTX 768MB
    Raptor 150GB
    NEC ND4550 16x16 DVD±RW
    Coolermaster 850W x3 12V
    Antec P180

    Custom built by $aunder$


  2. #2
    Senior Member
    Join Date
    Jul 2003
    Location
    ZA ✈ UK
    Posts
    622
    Thanks
    0
    Thanked
    0 times in 0 posts
    Ditch the Qtec, get an Antec. Solved.

  3. #3
    Senior Member
    Join Date
    Jul 2003
    Location
    South Wales OR Southampton Uni
    Posts
    2,105
    Thanks
    4
    Thanked
    3 times in 3 posts
    I think 3 pin connectors draw off the same as 4 pin molex connectors, they just have a different connector, with one extra wire, the sensor.
    I dont really know much about which devices use which voltages, but the red wire on the 4 pin molex's is a 5v line, and the yellow wire 12v, so maybe the drivers use both ?

    Also where are you getting those voltage readings from, is it a windows ? As it may not be accurate, the best way is to stick a multi-meter right in the 4 pin molex plugs and get a direct reading. I found that the windows reading of about 11.4/5V and 5.4V was wrong, and was actualy about 11.8/9 and 5.6V. Im not sure how you can check the 3.3v line ... that itsn't output on any accesible plugs, myabe only through the ATX conector, i dont know.
    Last edited by Lexeus; 22-11-2003 at 08:11 PM.
    Desktop: AMD Athlon XP 2500+ Barton, 1024Mb PC-3200 TwinMOS w/Winbond, MSI K7N2 Delta-ILSR, Radeon 9800SE AIW, 40 GB 7,200 Rpm Hitachi Deskstar, 120GB 7,200 Rpm 8mb Cache Maxtor Diamond 9, 160GB 7200 Rpm 8mb Cache Seagate 7200.7 SATA, Plextor 708A 8x DVD-RW, 550W PFC Q-tec PSU, Casetek 1019SM Silver Case, Camdridge Soundworks DTT2200 Speakers

    Laptop: Clevo D470W - 17" Widescreen TFT, Intel Pentium4 3.06Ghz 533FSB, 1024Mb PC-2700 Hynix, Radeon Mobility 9000 64Mb, Fujitsu 80Gb 4,200rpm, 250Gb 7,2000rpm 8mb Cache Maxtor OneTouch, Toshiba SD-R6372 DVD-RW +/- x4, Built-in Four speakers, webcam and microphone

  4. #4
    HEXUS webmaster Steve's Avatar
    Join Date
    Nov 2003
    Location
    Bristol
    Posts
    14,268
    Thanks
    286
    Thanked
    828 times in 468 posts
    • Steve's system
      • CPU:
      • Intel i3-350M 2.27GHz
      • Memory:
      • 8GiB Crucial DDR3
      • Storage:
      • 320GB HDD
      • Graphics card(s):
      • Intel HD3000
      • Operating System:
      • Ubuntu 11.10
    Right...

    5V is used for devices like PCI cards, a lot of the circuitry on the motherboard, and the controller circuitry for drives.

    12V is used for motors, fans and devices that take a lot of juice (eg powerful graphics cards.) It might also be used for CPU/memory circuits fred through mosfets and caps - not sure about that though.

    The 3.3V line is mobo stuff again - they're the orange cables on the ATX connector.

    5V is probably the most important when it comes to overclocking - a lot of circuitry relies on it. 12V is a bit difference. The ATX standards tolerance for 12V is +/- 10% whereas it's 5% on other lines. As long as you're above 11 you should be OK really.

    Still, Antec PSU's are the ones to go for, because they have separate circuits for the 3.3, 5 and 12V rails - unlike other PSU's which simply use one or two and "share" them.
    PHP Code:
    $s = new signature();
    $s->sarcasm()->intellect()->font('Courier New')->display(); 

  5. #5
    Member
    Join Date
    Nov 2003
    Location
    Wales
    Posts
    174
    Thanks
    0
    Thanked
    0 times in 0 posts
    Thanks unts (and the rest of the guys for your comments), I wasn't quite sure, thanks for clarifying. So 11.74 on a 12v rail should be ok? My 5v doesn't drop below 4.96 .......
    C2Q6600 @ 3.15GHz
    ThermalTake MiniType90
    EVGA 680SLI
    4GB OCZ Reaper 1066MHz @ 1000 4,4,4,15
    EVGA 8800GTX 768MB
    Raptor 150GB
    NEC ND4550 16x16 DVD±RW
    Coolermaster 850W x3 12V
    Antec P180

    Custom built by $aunder$


  6. #6
    HEXUS.social member Agent's Avatar
    Join Date
    Jul 2003
    Location
    Internet
    Posts
    19,158
    Thanks
    732
    Thanked
    1,604 times in 1,043 posts
    Originally posted by madwelshboy
    Thanks unts (and the rest of the guys for your comments), I wasn't quite sure, thanks for clarifying. So 11.74 on a 12v rail should be ok? My 5v doesn't drop below 4.96 .......
    It should be, but seriously look at getting a better PSU. Q-tec are one of the worst makes out. Known for unrelability.
    Use the search feature at the bottom and you'll see a few threads on them
    Quote Originally Posted by Saracen View Post
    And by trying to force me to like small pants, they've alienated me.

  7. #7
    Senior Member SilentDeath's Avatar
    Join Date
    Aug 2003
    Posts
    4,745
    Thanks
    38
    Thanked
    16 times in 11 posts
    Still, Antec PSU's are the ones to go for, because they have separate circuits for the 3.3, 5 and 12V rails - unlike other PSU's which simply use one or two and "share" them.
    not sure what you mean by that.. but most power supplys use different windings on the secondry coil of the transformer for different voltages... 3.3, 5 and 12v are all serperate...

  8. #8
    Senior Member
    Join Date
    Jul 2003
    Location
    New Orleans - baby!
    Posts
    340
    Thanks
    0
    Thanked
    0 times in 0 posts


    My voltage has always been out of wack and my computer is rock solid/stable.

  9. #9
    '~'+'~' Enverex's Avatar
    Join Date
    Oct 2003
    Location
    West Midlands
    Posts
    901
    Thanks
    0
    Thanked
    0 times in 0 posts
    • Enverex's system
      • Motherboard:
      • Gigabyte H77n-WiFi
      • CPU:
      • Intel i5-3570K with Scythe Shuriken
      • Memory:
      • 16GB Crucial Ballistix Tactical 1600Mhz
      • Storage:
      • Samsung 840 500GB SSD
      • Graphics card(s):
      • MSI GTX 670 2GB OC Power Edition
      • PSU:
      • EVGA SuperNOVA 550W G2
      • Case:
      • Silverstone Sugo SG11
      • Operating System:
      • Windows 10 Pro 64bit
      • Monitor(s):
      • LG 42LW550T 42" TV
      • Internet:
      • BT Infinity
    Those voltages are all fine, so there isn't any reason why it would be unstable. 3.3 is still safe, and not important anyway, 12v is well within limits, and the 5v being higher will help keep your system more stable when overclocking...

    NS

  10. #10
    Senior Member
    Join Date
    Jul 2003
    Location
    Petersfield, UK
    Posts
    1,755
    Thanks
    0
    Thanked
    0 times in 0 posts
    What about the minus rails?

    There is the -12v one at -8.25v is that ok or not?

    Time for me to download sandra again

    Will
    | XP1600-m | ASUS AN78X Deluxe | r9700 pro | 2x512mb pc37000 |

  11. #11
    Member
    Join Date
    Nov 2003
    Location
    Wales
    Posts
    174
    Thanks
    0
    Thanked
    0 times in 0 posts
    Hey chrisf6969,

    Nice to see you again, great clock, good to know. Thanks.
    C2Q6600 @ 3.15GHz
    ThermalTake MiniType90
    EVGA 680SLI
    4GB OCZ Reaper 1066MHz @ 1000 4,4,4,15
    EVGA 8800GTX 768MB
    Raptor 150GB
    NEC ND4550 16x16 DVD±RW
    Coolermaster 850W x3 12V
    Antec P180

    Custom built by $aunder$


Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •