TechSpot

Bad PSU?

By soulburn2k5
Jan 20, 2010
  1. ok so i recently build a new pc everything new except the dvd drive which i took from my old pc. the thing is i'm wondering if my psu has insufficient power to run it as,

    well here is the tricky thing, if i use my new graphics card and try to play any kind of 3d game or badaboom my computer either instantly restarts or does a blue screen after maybe 20 minutes sometimes as little as 60 seconds.

    but, if i use my old graphics card which doesn't require any power connectors from the psu everything runs fine apart from the occasional random restart (which doesn't happen a lot) i have ran memtest just to see if it is the memory did about 300% coverage with no errors. could this be a psu problem or maybe an faulty graphics card?
     
  2. yangly18

    yangly18 TS Rookie Posts: 242

    please list your computer specs, this will help figure out if it is a power problem. thanks.
     
  3. soulburn2k5

    soulburn2k5 TS Rookie Topic Starter

    Sure, Specs are like this

    mainboard: Nvidia 6100PM-M2 (v3)

    CPU: Athlon II X4 620 @2.6Ghz (stock cooler)

    Memory: 2GB generic @800Mhz

    Graphics: Nvidia GTS250 1GB

    HDD: 250GB Sata

    OS: windows XP home SP2

    Power supply is a Generic 550 watts it came with my case

    (edit) the graphics card i use that doesnt give me blue screen is Radeon HD 3650
     
  4. yangly18

    yangly18 TS Rookie Posts: 242

    one moment, im going to check it out hopefully wont take too long.


    EDIT: Alright, well I am not expert at how power supplies distribute their power amongst the computer, but an average computer designed to play 3D games usually has a higher PSU Wattage. With a second look at what you said, it looks like it could be a driver fault, in which case i suggest you see if there are any new drivers that have come out for your graphics card. Since you said it is all new stuff, this is most likely the case, since there have been new drivers developed for the card since it was made. Since you said that power supply came with the case and its some generic brand, i would highly suggest you get at least a 650W brand name one, just for reliability issues.

    HEREis the NVidia site where you can find all their latest drivers.




    Try upading that driver and tell me if there is still an issue. thanks
     
  5. dividebyzero

    dividebyzero trainee n00b Posts: 4,973   +741

    This doesn't sound promising.

    Can you list the model of the case/psu combo- and provide a link if possible
    There's a good chance that your "550 watts" is somewhat less than that figure.
    There should be a sticker attached to the PSU with the details of the unit.
    Manufacturer and model number ?
    +12v amperage (this may be listed as 12v1, 12v2 etc.) ?
     
  6. soulburn2k5

    soulburn2k5 TS Rookie Topic Starter

    well i did already try to update the drivers, all drivers infact, (chipset, sound, graphics etc) with no luck,

    i give psu details

    Manufacturer: Cit
    Model: 500U
    Max dc output: 12v1=14a 12v2 13a
    Peak Output: 500w so i'm guessing its actually a 500 watt and not a 550?

    (edit) http://www.aone.co.uk/ProdInfo.ASP?ProductID=2462 here is a link that shows the psu
     
  7. dividebyzero

    dividebyzero trainee n00b Posts: 4,973   +741

    The HD 3650 is a low power consumption card. It requires no extra power cable as it draws what it need through the slot it sits in.
    The GTS 250 on the other hand requires a 6 pin power connection in addition to the slot- so I'm guessing you have connected 2 molex on one of the cables to a 6pin for the card.
    The best you can hope for is connecting 1 molex from each cable (if the molex are on 2 or more cables) rather than both on 1 cable. But I would strongly suggest that you ditch the PSU (or sell it) and buy a branded PSU with at least 34-36 amps on the +12v rails and a dedicated 6 pin PCIe connector if possible.
     
  8. soulburn2k5

    soulburn2k5 TS Rookie Topic Starter

    not sure i understand what you mean, the molex i use both have wires coming out of other molex so are u saying find a psu that has either independent molex or a dedicated PCI-e connector? if so is this likly to solve the blue screen problem or would that just be for added stability? because at first i thought maybe its the psu not able to power the card but now i'm reading elsewhere that it should run fine on a 450w so maybe its just faulty?
     
  9. soulburn2k5

    soulburn2k5 TS Rookie Topic Starter

    everything seems to be working ok now, touch wood. all i did was replace my old graphics card wipe all the driverswith hijack this, installed the new one i tried badaboom again but that crashed my computer so i removed it completly, up untill now it hasn't crashed since, really strange, thanks all for your help
     
  10. dividebyzero

    dividebyzero trainee n00b Posts: 4,973   +741

    The PSU's wattage is adequate-unfortunately a good percentage of it's power is being converted straight to heat. As it's a unit made for a Pentium 4 system a large percentage of it's output is dedicated to the +3.3 and +5 voltage rails. I'd be surprised if the PSU is delivering much more than 300 watts on the 12 volt rail
    Amperage determinines the effectiveness of a PSU and 27 combined amps is at best marginal for an nVidia chipset motherboard + GTS 250.
    Power delivery/Graphics Instability and BSOD are, in this case the same thing.
    If you replace the unit with one that is of ATX 2.0 standard or better it will have the 6pin PCIe connector and a power distribution better suited for the card you have, and if you want a stable system ensure that it's +12v amperage is at least 34-36.
     
  11. soulburn2k5

    soulburn2k5 TS Rookie Topic Starter

    sounds expensive, i dont know if you can tell from my system setup but i'm on a budget so i cant really afford the good power supplies i found one the other day that is around 30 amps with a pci-e connector for pretty cheap, so i guess i'll go for that one, the higher the amperage the higher the price kinda like graphics cards with 128 bit interfaces vs 256 bit interfaces
     
     
  12. dividebyzero

    dividebyzero trainee n00b Posts: 4,973   +741

    Yep, thats pretty much it. You get what you pay for.
    Usually a failing component is a swap-out. With a PSU if it fails it can take out most of your system. Every voltage fluctuation you get when gaming or transcoding (when the card is drawing the most power) is probably having a detrimental effect on both it and your harddrive.
     
  13. soulburn2k5

    soulburn2k5 TS Rookie Topic Starter

    i guess thats why it crahsed on graphicaly intense games like UT3 and arkum asylum as its running fine i think i'll just avoid games like that and save till i can afford a decent psu, hopefully i can get a good enough one that i dont have to worry for a few years like a 750 watt or 1k
     
  14. dividebyzero

    dividebyzero trainee n00b Posts: 4,973   +741

    A good specced 520-550 would be fine for a single card like the GTS 250.
    http://www.newegg.com/Product/Product.aspx?Item=N82E16817702010
    Detailed spec here-note the 12v rails amperage
    http://www.bfgtech.com/bfgr550wgspsu.aspx
    If you plan on upgrading in the short-medium term then a good 600-700 would support pretty much any card.
    http://www.newegg.com/Product/Product.aspx?Item=N82E16817341019
    http://www.newegg.com/Product/Product.aspx?Item=N82E16817139005
    http://www.newegg.com/Product/Product.aspx?Item=N82E16817341018
     
  15. soulburn2k5

    soulburn2k5 TS Rookie Topic Starter

    hey thanks alot, really good of you to suggest psu, i like the first one, its within my price range well they all are really, but i have to think about shipping costs and such, thanks tho
     
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