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I have a Geforce 9600 GSO working with a Intel DP45G (or something like that) and a 730W power supply. When I switch to a Radeon HD 6990 I have no video.

  • The GPU fan is spinning
  • The boot produces only the expected beep
  • The power supply is 20W weaker than required
  • The power supply has 2 x6-pin connectors instead of the required 8-pin connectors, but the card came with adapters.
  • The card has a 1-2 switch, which I guess is for the crossfire, I tested in both modes.

What seems to be the cause of the problem? A malfunctioning card?

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Do you get any output from the onboard video port (if there is one?) – tombull89 Jun 15 '11 at 12:30
@tombull89 there is none – Jader Dias Jun 15 '11 at 12:31

You should post exactly what PSU you are using, as this is a crucial requirement for the HD 6990. But i will go ahead and post my findings anyway.

From the AMD Gaming Forums the powerdraw can be up to : 150W + 150W + 75W = 375W. But a special Overamp feature allows it to consume 187.5W from the two 8-pins connectors. So all in all the card can draw up to 450W of power, where the 75W comes from the PCI Express slot itself.

Then there are the power connectors. For 6-pin the maximum is 75 Watts, while the maximum is 150 Watts(187.5W) for 8-pin. Link is here.

Also it is a good idea to try out the card in another system, to make sure that the card is actually in working order. However this might be difficult with this card.

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My PSU…-17-152-036--Product – Jader Dias Jun 15 '11 at 13:01
One item of concern is that it is not listed as a certified power supply . I would probably install the PSU+GFX card into another system to verify that the components work together. – Sharken Jun 15 '11 at 13:41
up vote 2 down vote accepted

My motherboard was fried in the process and I couldn't figure out the exact cause of the problem.

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That solves that problem . . . – surfasb Jul 13 '11 at 21:43

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