I have an HP 8570C, built in 1998, with a PIII 450 with MMX processor. The system powers a Ti4600, CD ROM, CD-R, plus hard drive and 3.5 inch drive. The souond card is on the motherboard.The power supply is a 160 watt, and is 4 years old. Sounds like a 250 watt power supply should be plenty?Thoughts.Rick

If you're buying a new one... or getting a new case with power supply built-in, why not get a 300? I don't have figures in front of me, but I'd hazard a guess that there's not a very big price difference and if you're going to upgrade in the future, you'll need a 300 watt supply. I would guess that 250 watt is enough for your system, but I wouldn't say I'm 100% sure.Cheers,Simon.

Jeez that system is just about underpowered LOL. A 175W powered my old 486 system for years LOL.My older Krap6-400 system uses a 230W AT power supply and it powers: the VIA MVP3 motherboard with K6 CPU and 192MB RAM (64MB + 128MB), a WD Caviar AC26400 6GB HD, a WD Caviar WD200BB 20GB HD, a EONtronics Lithith Banshee 16MB, a ESS AudioDrive ES1938 soundcard, a SMC 1211TX network card, a Lucent 56K WinModem (not used), a Actima 36x CD-ROM, and a broke Mitsumi floppy drive. I know exactly whats inside because I built it in early 1999.I put in a 500W in my new 1.2GHz system because I knew that I was gonna upgrade it a lot and a lot of power might be needed.