Geforce 250GTS on a 570W PSU; why isn't it working?

Hi everyone, i have a question for you PSU experts..

So i have a computer that i built in early 2006 with the following spec:

- SkyHawk Power ONE 570W power supply

- AMD 3800 X2 processor (OC'd to 2.4 ghz)

- DFI Lanparty NF4 Ultra-D motherboard

- 2gb (2 x 1gb) G.SKILL DDR 500 memory

- Geforce 7800GT video card

- Hard drive i don't quite remember i think its a 250gb Seagate SATA

- Edemax PCI wireless network card

So here is my problem:

I recently bought a Geforce 250 GTS video card to replace the 7800gt, but when i switched them my computer stopped booting up properly and the screen stopped coming on. I also noticed that the system fans aren't quite as vigorous when i turn the computer on.

Now, i know it seems pretty obvious that the problem is the PSU not being powerful enough, but from what i've been reading it seems like 570W should be plenty for this video card.

The Nvidia website says you need a PSU of at least 450W for this card and im well above that.

That's why im comfused.. And i guess im just trying to figure out if maybe i was sent a defective video card before spending more money on a new PSU.

Thanks in advance for any help
12 answers Last reply
More about geforce 250gts 570w working
  1. Did you delete the drivers for the old video card and install the new drivers for the new card?
  2. You should stick in your 7800GT and update the BIOS. Some older PCI-E 1.0 boards will have issues with PCI-E 2.0 cards. Updating the BIOS may provide you with a work around for this issue. If your board is an early revision you could just be SOL, but you need to check with DFI to be sure :D

    As for the PSU, how many amps does it have on the 12 rail? Just because it's a 570W unit does not mean it can provide enough 12v power to run your GTX250.
  3. Hey guys..

    I did uninstall the previous drivers, but i didn't install the new ones before switching the cards.. Is that what you mean Johnny?

    I will try updating the bios on my mobo and see if that works..

    The 12v rail has 20 amps on it, is that enough?
  4. After doing some research on my power supply, i've found out that there is a problem with this line of PSU.

    All the 12v rails are connected to the same location on the PCB inside the PSU whereas normally they are all supposed to have their own connections.

    So basically all the 12v rails are split off of one.

    I'm guessing that might be the problem.

    Still, it worked before.. So im still unsure.
  5. Yes. The typical procedure is to install the new drivers before installing the card. Also check for newer up to date drivers. Sometimes there are glitches and issues. megamanx00 made an excellent suggestion about updating the BIOS.

    A 570 watt power supply with only 20 amps on a 12 volt rail? That's not good. Is there more than one 12 volt rail? Sometimes they are listed as 12v1 and 12v2. A high quality 550 watt psu will show about 40 amps on the 12 volt rail(s).
  6. kuskus said:
    So basically all the 12v rails are split off of one.

    Most if not all PSU's are like that.
  7. It is not unusual to find psu's advertised as having mutiple 12 volt rails that are actually one large 12 volt rail. It is an advertising gimmick. However, there are some high quality power supplies that really have genuine bonafide mutiple 12 volt rails. For the typical user it is not going make much of a difference and should not be a concern.
  8. Ok i will try updating the bios and installing the drivers before hand when i get home from work.

    The PSU spec lists +12V1 and +12V2 each with 20 amps.. Does that mean it really has 40 amps?

    As far as what i was saying about the 12V rails being split off of one, from what i was reading in order for a PSU to comply with the Intel EPS12V V2.1 and AMD ATX-GES guidelines all the 12V rails are supposed to have their own connections on the PCB.. And the article i was reading made a big deal about that (and the fact that the packaging of these PSUs erroneously claims that they do comply with those standards.)

    But again, i don't know how much that matters in this case. As you can see i'm certainly not that knowledgeable about PSUs in general.

    Thanks a lot for the help guys!
  9. The answer to your question is it depends. Sometimes the actual combined total is a little lower and sometimes it is a little higher.
  10. After doing a little more research i'm starting to think that the problem may be the motherboard..

    I found threads from people trying to use the same mobo with newer generation (pcie 2.0) cards and having the exact same symptoms as me.

    And the BIOS hasn't been updated since 2005 so i'm not sure this video card is ever going to work in my current system. I can't afford to upgrade all the other stuff right now so i might just send this new video card back and be done with it.
  11. Yeah I think that PSU would be one problem, and your motherboard another. For one it may not be safe to run that card with that PSU. For another without a BIOS update to resolve your bards issues with PCI-E 2.0 you may just be SOL. For the older PCI-E standard I think the best you could reasonably do would be a G80 GPU like the 8800 GTS 640MB or the old 8800GTX if you can get it cheap. Of course, before you go off and buy one make sure to check if anyone else has problems with such a card and your motherboard just to be safe :D.
  12. major bummer!!!
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