New video card has 3 pin connector cable only has 2 pins

HP M9600T desktop, trying to replace video card. New card is GeForce 9600 GS. The old card had a 2 pin connector. The new card has a 3 pin connector. On the motherboard it appears labeled SPDIF OUT 2, on the new card it appears to be labeled SPDIF IN. But as I said the new card has a 3 pin connector and the existing cable from the motherboard has a 2 pin connector. First question - does this cable HAVE to be connected? If yes, what do I do? Thanks in advance for helping this dumb old man.

Hi and Welcome!

no, you don’t need this connector unless you want to use the HDMI port to feed video and audio to your TV (which of course needs HDMI inputs then).