I have 3 HDDs and 1 DVD drive. But I am not able to run more than any two of them together. Is it a SMPS issue ? I have 450W SMPS and have graphics card installed (Asus EAH6670). Whenever I connect third SATA drive, one of it (randomly) stops functioning. I can run ANY two without any problems. When a HDD does not work, it gives beep beep sound too.