PSA: Power supply actual requirements

wogg - this is very good information and I applaud you for posting it. however, I just wanted to point out that I wouldn't try to go with the MINIMUM possible wattage for a new build. In the engineering world (of which I'm a part, and IIRC, so are you), you never design a system to minimum specs because of tolerance stackups, transient possibilites and component degradation over time.

for example, on your mid-range example with a fanless video card using less power consumption than the high end Radeon, you're stating that you'd pull less than 250W at full load. I would not recommend getting a 250W power supply for that system, but I'd go with something at least 280W or 300W just to make sure that all transients and time degradation of components don't leave me out in the dark during a critical time. the difference in price between a 250W power supply and a 300W power supply is really neglible when considering the safety margin you're allowing yourself for those extra few watts.

so while I completely agree with you that it is advisable to get a lower wattage power supply than all the hyped up home builders would recommend, I also would not drop to the minimum specs required for full load, but leave a little bit of "breathing room"

Yes, also very good points and I agree! the 400W-500W supplies (complete with ATX+12 ) are good price points and would be an excellent choice for a system pulling ~250W at full load.

and while I also advocate having a decent video card with some dedicated memory, I also agree it's not necessary to have a 130W+ video card for a DAW unless you're gaming on it also! I think a fanless 128M or 256M video card will do a great job for a DAW and will consume less power and allow the builder to purchase a more reasonable power supply.