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Will 8800GT work with this PSU?

By PlayerXM
Mar 3, 2008
  1. Hi, I'm going to buy a GeForce 8800GT and I have a 380 Watt PSU: Seasonic S12 380W.

    I'm not sure if it can handle the 8800GT card. Here are specs for the PSU (I'm not good at that stuff so I'll post all I can find that I think could be relevant):

    ATX12V V2.0
    PCI-E Connector (6P)
    +12V1 - 10A
    +12V2 - 15A
     
  2. tastegw

    tastegw TS Enthusiast Posts: 188

    this was taken from tigerdirect on this 8800gt
    http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=3485042&CatId=1839
     
  3. PlayerXM

    PlayerXM TS Rookie Topic Starter

    Ok, I don't have a X6800, only an e2180 and 1 HDD, will that affect the 28A requirement? I have a second PSU with 25A on +12V (I assum this is the PCI-E connector).
     
  4. tastegw

    tastegw TS Enthusiast Posts: 188

    try this calculator from newegg.com

    http://educations.newegg.com/tool/psucalc/index.html

    after you enter in everything, add about 30% more power and that should give you a safe number to work with.

    personally, i would not run anything lower than 500w's with any of the 8800's just to be on the safe side.

    i run the 8800gts (few points below the 8800gt) with a 600w psu. it gives me no troubles and plenty of "upgrade" room for other components.

    hope the calculator works out for ya.
     
  5. Matthew

    Matthew TechSpot Staff Posts: 5,268   +92

    Their calculator gives loads of headroom. You might, might get away with that PSU powering your system but it'd seriously be pushing it with only 25A on the 12v rail. Last time I checked it was recommended that you have at the minimum of 32A on the 12v rail for an 8800GT.

    Try it and if it doesn't work, then, no harm done, you'll know you need to upgrade your PSU.
     
  6. jonmcc33

    jonmcc33 TS Rookie Posts: 60

  7. kpo6969

    kpo6969 TS Maniac Posts: 710

  8. kpo6969

    kpo6969 TS Maniac Posts: 710

    It will probably work for now but start looking for an upgrade.
    The party line from Nvidia is 450w @ 26amps. eVGA states 400w @ 22amps for my 8800GT (I use 470w @ 26amps)
    The 425w @ 28amps is on a OC2 card. The higher the clocks, more power would be needed. Also if you had an X6800 Extreme cpu we probably wouldn't be talking about this to start.
     
  9. jonmcc33

    jonmcc33 TS Rookie Posts: 60

    I'm fairly sure that he has it.
     
  10. kpo6969

    kpo6969 TS Maniac Posts: 710

    You think? I'm glad you cleared that up.
    My post was in reply to your post:
    "Seems to me that an 8800GT only requires a 200W PSU. Not sure where some of you talk about 500W..."
    And I replied:
    "You still need the required amperage."
    And your reply:
    "I'm fairly sure that he has it."
    What's the basis for your statement?

    How many 200w psu's have that required amperage?
    I'm not trying to give you a hard time, but when you interject yourself in a thread and post conflicting information you may lead someone to do something ill-advised.
     
  11. SNGX1275

    SNGX1275 TS Forces Special Posts: 10,714   +397

    200W PSU won't have the amperage as others have pointed out.

    The source of all this video card confusion is that when people see the recommended amperage listed for the card, that is listed for the total system, not what the card itself drinks. The reason nobody lists how much the card itself takes is because its difficult to measure.

    That 380W PSU has enough amperage on the combined 12V rails to handle the card, but I'd be concerned running the card on just 1 rail because neither one by themselves is that strong. (although in the following text I show it should work without any issues)

    [​IMG]

    My recommendation would be to use the molex to PCIe power adapter and pull from a molex on each 12V rail if possible (its hard to tell based on the images if you have that ability). If you can't do that, then hopefully the 12V rail that the PCIe connector is on is the 15A one. You'd probably be fine on just that 15A because the card would have to pull 144W assuming 80% efficiency of the PSU to go over what the rail is capable of (180Watts at 100% efficiency). Now in the anandtech link, the entire system was pulling 209W total system under load with more powerful hardware. Their processor was pulling 75W (if we assume it was also under load) and the HD was pulling (estimated) 10W then if we neglect everything else you'd have a maximum video card usage of 124W which is 10.3A for 12V (in reality it would be lower because other components would be using some power).

    So bottom line, looks like you can do it on a single 12V rail if its the 15A one. If possible I'd try to run it off of both just to be safe, but the math shows you can get by.


    The reason people 'guess' in posts is because it takes a long time to write up something like I just did. I spent probably 10-15 minutes checking links and doing the math.
     
  12. jonmcc33

    jonmcc33 TS Rookie Posts: 60

    I don't know of many 200W PSUs out there. The point is that he doesn't need a 450W and he sure doesn't need a 500W PSU.

    I just always laugh a little when I see people recommending power supplies like that or worse, a 1kW PSU for a pair of 8800GTX in SLI. Sorry, no offense to you of course.
     
  13. pretaz19

    pretaz19 TS Rookie

    im getting a 500w for my 8800gt
     
  14. SNGX1275

    SNGX1275 TS Forces Special Posts: 10,714   +397

    Myself, among others, have been trying pretty hard for the last few weeks to make sure people know its not about the rated wattage of the PSU, its the overall quality, and frequently cited amperage on 12V rail(s) that is important when running a higher end video card.

    So I hope for your sake (and ours in the future if you stick around) that you aren't buying a $25 500W PSU that weighs 2lbs. Because if you do you'll probably be posting back wondering why something broke or isn't working right.
     
  15. kpo6969

    kpo6969 TS Maniac Posts: 710

    8800GT SC
    http://www.evga.com/products/moreInfo.asp?pn=512-P3-N802-AR
    Minimum of a 400 Watt power supply.
    (Minimum recommended power supply with +12 Volt current rating of 22 Amp Amps.)
    I said 450w @ 26amps

    "I don't know of many 200W PSUs out there. The point is that he doesn't need a 450W and he sure doesn't need a 500W PSU." Your recommendation?

    "I just always laugh a little when I see people recommending power supplies like that or worse, a 1kW PSU for a pair of 8800GTX in SLI. Sorry, no offense to you of course."
    Hope you don't piss in your pants when the laugh's on you.
    I know a good 610w @ 49amp SLI certified that would do the job nicely
     
  16. jonmcc33

    jonmcc33 TS Rookie Posts: 60

    Thanks for the link from that video card vendor. I already showed you proof of actual power draw from AnandTech. If you want to dispute that then take it up with them.

    My recommendation? The Antec Earthwatts EA380 is overkill but it's an 80 Plus rating and has the single 6-pin PCIe connector that he needs. He can get it for around $50 or so.

    The Corsair HX620 was used to demo a pair of 8800GTX in SLI. Obviously you do not need a 1kW PSU for that. It took Tri-SLI to even get above 700W: http://www.anandtech.com/video/showdoc.aspx?i=3183&p=5
     
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