Hi guys I have an issue with the above mentioned graphics card, my system, Cmx45 mobo, Intel core 2 duo cpu, winpower 550W power supply, 3GB ddr2 800MHz ram, 2 x 500GB 1 x 1TB Hard Drives, x-fi extreme audio. I had a gts450 card in, worked perfectly. Now I tried my HD5770 and there's no display. When I plug the 6 pin power lead in the 5770 the fan runs, but when it's not plugged in the fan runs louder/faster, what's up with that? Anyway when the 5770 is plugged in and I boot up I get one beep, so all good. I haven't tried vga yet, only hdmi. I just want to know (at this point) Could it be my power supply? Thank you for taking the time to read this. Any suggestions?