Monitor uses a lot more than the PC. A lot depends on how much you use the PC, and whether any of that time that it is on, it goes into sleep mode or stand-by. There are too many variables in a PC. Number of fans, hard drives, CDROMS, Floppy, What kind of sound card and video card, integrated versus I/O or PCI Card. Peripheral devices, etc. Also, if you play games off of a CDROM, the computer has to run both the CDROM and the Hard Drive. Lots of variables. If you do not like my post feel free to point out your opinion or my errors.