I'm looking to upgrade my computer with an extra 4gb of RAM, a 1tb hard drive, and eventually an HD 5770 or 6870. My current PSU is a corsair 550 watt power supply. I want to know if that is enough to power all of these thing plus what I have currently.
Mobo: ASUS M4A79XTD EVO AM3 AMD 790X ATX AMD
RAM: G.SKILL Ripjaws 4gb (2x2gb) DDR3 1600
CPU: AMD Phenom II x4 955 Black Edition and a cooler master Hyper 212+ to cool it
Hard Drive: Samsung Spinpoint 320gb
Graphics Card: GTS 450 (I will be getting rid of this when I get the new one)
ODD: Dual layer DVD burner
Also, would it be worth it to upgrade to the HD 5770? Or am I just better off sticking with this until I get more money to go for a 6870?