This computer is " DELL 755 DESKTOP PC CORE 2 DUO 2.33 GHZ " , so What is the highest graphics/video card?

That can match with it. Also, i need a graphic card that have HDMI slot to connect to HDTV|||The Dell Optiplex 755 being a business computer, doesn't come with a very powerful power supply unit, so that will be an issue when adding in a video card.



Many cards nowadays require a power supply with a dedicated 6 pin PCIE power connector.



Your desktop most likely does not have one, so you're essentially limited to low power options like the Radeon 5450:



http://www.newegg.com/Product/Product.as…



You *could* also go for the Radeon 5550. It should work as long as you have a 300 watt or so power supply.

http://www.newegg.com/Product/Product.as…



All graphics cards have HDMI outputs nowadays.|||I can't understand your question. Try nividia 512mb or ATI 512MB DEDICATED GRAPHICS CARD.