Im planning on ordering a new graphics card on new egg today! I have a 500w Thermaltake TR2, the graphics card im getting has a minimum power supply requirement of 500W reccomened 550W. I probally need a new PSU. How can i determine how much wattage i will need altogether for computer? And i only have enough money to order one part at a time sooo if i do get the graphics card first is it safe to plug it in and play or would that possibly blow the PSU and conponents? Help please -Thanks Brandon