Hi all, long time lurker/surfer of SPCR, first time poster.

I'm building a PC out of old parts to run a webcam 24x7 or maybe 12x7. The PC will be an all in one Gigabyte GA-MA785GM-US2H rev 1.0, Sempron 140 (probably left at stock 2.7GHz), 2x1GB RAM, Hitachi 5K320-160 2.5" 160GB 5400RPM drive, a Logitech usb webcam and no other peripherals.

My goal is low power, low noise and no additional cost. I have 3 spare ATX power supplies:
Antec SL350
Enermax EG365P-VE (no sata power connectors)
Antec True550 (no sata power connectors)

I'm guessing the board/cpu/ram/drive will draw something low, like 50w at idle, maybe 90w under load. Does that sound right? The max load should be way below 350w so all the power supplies should be sufficient.

What about efficiency, noise and reliability? I have a kill-a-watt and can cycle through them but I'd like to find the board's thoughts. Especially if one of these units is particularly good or bad or can be improved with easy mods, e.g. unplugging a fan.

Thanks! jxf011

PS - I also dug up an Antex PP-303X 300W and an Enlight EN-8234942 235W but they both lack a 12V 2x2 power connecter that the other 3 power supplies have and I think the Gigabytes requires.

I got my new board that's replacing the GA-MA785GM-US2H and did some quick testing with no OS:
GA-880GM-USB3 rev 3.1
Sempron 140 2.7GHz, default settings (will go in the old board eventually)
4x2GB Samsung DDR3 PC3-10600 (stays with the new board)
heatsink, no fan
PS2 keyboard

Results with a Kill-a-Watt, watts in bios/watts at no OS screen:
74-76/72 - Antec SL350 >> very quiet but a bit of a rattle, like a knocking, tick tick tick ...
71-72/69 - Enermax EG365P-VE >> louder than the Antec but still quiet and the sound was smooth
FAIL/FAIL - Antec True550 >> came up as 27 watts but the monitor never got video and no beep codes. Reconnected everything and same thing. I will discect this PS for parts after a while.

So the power winner seems to be the Enermax EG365P-VE.

Any thoughts on modding the Enermax to reduce the noise? Disconnect the 92mm or 80mm? Should any of the vents be covered if I unplug a fan? My thought is to unplug the 92mm and cover the bottom so the 80mm pulls across the inner heatsinks. Also, would it be better for PS cooling to run it with the disabled 92mm on top or on bottom? I'd think it'd be best to have the board low and the disabled 92mm high. Any ideas?