Here are specs on my power supply:
+3.3V@30A, +5V@30A, +12V1@14A, +12V2@15A, -12V@0.8A, +5VSB@2A
A 4850 requires a 450w power supply and 1 6 pin power connector ,but the S12 isn't a cheapo unit. Also, I only have 1 optical drive, 1 HD, and about 6 fans. I think I should be ok?