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Geforce 8800 GTS power plug in?

Last response: in Graphics & Displays
February 20, 2008 4:47:58 AM

The Almighty Google failed me and I couldn't find the answer.

I have a EVEA Geforce 8800GTS 320mb card. My power supply is a 600 Watt ATX supply. It says it has 18A on the "+12V1" and 20A on the "+12V2". The power supply has two cables labeled 12V1 and 12V2, which plug into the PCI-E power connector on my card. I assume that it needs both 12V1 and 12V2 to add up to a total requirement of 26 amps, correct? The GTS card only has 1 connector, however. The card shipped with a y-adapter that connects to two molex cable ends and plugs into the card. Will this work? Will this give it the 26A it needs to work? I'm afraid I don't know alot about PSUs :pfff: 

February 20, 2008 5:00:33 AM

The card itself does not need 26 amps. A loaded system as a whole with that card needs 26 amps. You can use either pci-e power cable, may as well go with 12v2.

To know if your power supply has 26 amps combined on the 12v rails, we need to now the exact model, or you need to look at the label and see what the max combined is. Rarely if ever does 18 amp and 20 amp rails mean 38 amp combined. For example, the Antec SmartPower II 500W power supply has 17 amp and 19 amp 12v rails, but max combined is 25 amps. While the Antec Earthwatts 500W has two 17 amp 12v rails with a max combined of 34 amps.
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a c 144 ) Power supply
February 20, 2008 7:14:31 AM

A 320 MB 8800GTS needs about 100 - 110 watts, less than 10 amps. That 10 amps will be split between the motherboard and the 6 pin connector.

Technical note: You do not have a "12V2 cable". "12V1" and "12V2" are the names of the two 12 volt rails. Without opening up the PSU (and invalidating the warrantee) and looking inside (assuming you know what to look for), you cannot determine with outputs and cables are connected to which rails.

So. Look inside the computer. Pick a 6 pin connector. Plug it into the video card.

The 2X Molex adapter should only be used if the PSU doesn't have the 6 pin connector. And if the PSU does NOT have the 6 pin connector, it probably also does not have an adequate amount of 12 volt power.
a b Î Nvidia
a c 139 ) Power supply
February 20, 2008 8:23:19 AM


I can't tell what the max combined amperage is. It only lists max combined watts.
I can't tell what the max combined amperage is. It only lists max combined watts.
Total 12V amperage = Watts divided by Volts. In this case 420 divided by 12.
Should I not use the 2x Molex adapter
Should I not use the 2x Molex adapter
You should not.

Even before you plug in a PCI-e connector the video card can suck up 75Watts though the PCI-e slot. Thats why less powerful cards dont require PCI-e connectors. By adding a 6-pin PCI-e connector you're making another 75Watts available to the video card. If you had, for example, an 8800 Ultra with its two PCI-e connectors you'd be providing up to an additional 75Watts again.

February 20, 2008 3:16:03 PM

Wow, such quick help. I really appreciate it, everyone. All that answers my question. Thanks!