ATi Radeon HD 2900 XT setup

I bought a used ATI Radeon HD 2900 Xt card.  It did not come with a users manual.  I connected the power cable ( 6 pin connector) to the port toward the back of the computer.  I works ok.  But I get a warning message saying that the power supply may not be adequate / or the  clock setting may have been turned down, the card therefore may not work to the maximum capacity.   The screen goes black from time to time for a second or two.  Should I connect additional 6 pin power to the other socket?   ATi web site is of no help.

Can someone help me how to correct this problem?

lsage:

I bought a used ATI Radeon HD 2900 Xt card.  It did not come with a users manual.  I connected the power cable ( 6 pin connector) to the port toward the back of the computer.  I works ok.  But I get a warning message saying that the power supply may not be adequate / or the  clock setting may have been turned down, the card therefore may not work to the maximum capacity.   The screen goes black from time to time for a second or two.  Should I connect additional 6 pin power to the other socket?   ATi web site is of no help.

Can someone help me how to correct this problem?

Yes you should have a 6 and a 8 pin connector on that card for it to get the power it needs. If you can't find one on your PSU you can order a adapter.

Indeed like bob said you need to connect both the 6 and 8 pin on the vid card. the connectors are shown in the top right of the picture.

Nice PIC there, Der!