Power supply for My pc

Hello everyone i am planning to upgrade to a 4870x2 for my q6600 (2.4ghz no overclock), 4gb high performance 8500 ddr2 ram. i already have a 550 watt power supply in there. Will that be sufficient for this card? I am not a totally heavy gamer but i want to play crysis now and then and i heard this card runs hot and draws a lot of power. My pc usually runs around 30-40 degress per core so will this card cause any problems. i would appreciate any help. thanks in advance