So if i wanted the greatest possible power efficiency out of my computer...

[dug777]

Rather than getting a big ass 500w as seems to be the norm today?

Or even with lower power stuff, picking up a decent shuttle psu with beefy rails...

Since, as i understand it, efficiency increases as the PSU loads up?

Asplain me

 

[frostedflakes]

Power supplies are generally most efficient at about 50-75% of their max load. Below that efficiency typically drops off sharply, and above that it drops off slightly. SilentPCReview has a very good power supply testing setup, not just with sound but also efficiency, power factor, etc. You might want to check out some of their PSU reviews for get a feel for power supply efficiency curve.

I wouldn't worry about it too much, though. Just don't get something ridiculously overpowered (i.e. a 600w for a single-core system w/integrated video) and you should be fine.

 

[myocardia]

Power supplies are most efficient at around 75-80% of their output capability. Nothing works/runs better at 100%. For instance, which would you think would be able to make the drive from CA to NY? A Kia that's running in 5th gear, or a Rolls Royce that's in first gear, assuming both are traveling at 70 mph.

 

[f4phantom2500]

Originally posted by: myocardia
Power supplies are most efficient at around 75-80% of their output capability. Nothing works/runs better at 100%. For instance, which would you think would be able to make the drive from CA to NY? A Kia that's running in 5th gear, or a Rolls Royce that's in first gear, assuming both are traveling at 70 mph.

Yeah, since the efficiency drops off at higher loads, and since that's just generally putting a lot of stress on the power supply and leaving you no overhead, your system would be much more efficient and stable if you bought a quality higher watt power supply.

 

[Yellowbeard]

And, on the upper end, PSU noise increases as you get closer to 100% output. I would imagine that one would not last as long at 100% load as it would at 65% load.