What do you have in your system to strain a 300W Sparkle PS Mday? I have 3 7200RPM HD's, a 15kRPM HD, 5 PCI cards, a CLAP2, a CDROM drive, a CDR drive, a DVD drive, and 4 USB peripherals powered by the bus. They were all running on fine on the 300W PS that came with my case, an AOpen HX-08.