Originally Posted by AbidNibBeE
against my better judgement I am going to enter this debate.....
on the surface more wattage is better.
overall wattage is only one of many measurements of a PSU
The wattage is divided between usually three sets of output.
There are some low powered PSU's that have superior connection ability, superior cooling, and superior components.
evaluating a PSU by wattage only is like saying that lakes are better for sailing than oceans.
like with audio equipment, wattage of a component is not even close to the only measurement that matters.
I own two OCZ 600 watt PSU's, both manufactured with similar components, both with equal connection options. One runs with 600W divided three ways, 155, 580, and 20 watts. It provides 4 18A rails of power for CPU, CPU2/PCIe1, MB Accessories, and PCIe2. The other runs 600W divided four ways, 150, 504, 3.6, and 12.5, this one only has 2 25A and a .3A rail. Which one do you think has more connection options and provides smoother power across the whole system?
The answer depends more on the quality of the PSU. The higher quality PSU wins in terms of providing a superior quality of power. Sometimes the quality is more important than the capacity, especially when you know the capacity will be more than enough for a long time to come.
So when it comes to building a system like this that has extremely low power requirements (and always will), there's absolutely no need whatsoever to get a PSU that has a capacity over 350-400W. Seriously: he's not a gamer, he never will be, he will never have, or need, a powerful video card, and the majority of the work will be done with the CPU. Even if he does get a video card, it will not warrant the need for a PSU that has a capacity any greater than 400W because the only video card he can get right now that would begin coming close to needing a slightly larger capacity than 400W is the 7970 - but that's only if he overclocked the 3770K to 5 GHz at the same time. Even then, he'd have to have a simultaneous maximum load on the 7970 and overclocked 3770K at the same time. Since he's not a gamer, that would never happen. So, a quality-made 400W PSU would be overkill.
To take it further, each new generation of GPUs and CPUs require less power than the previous. So the argument of "future upgrades" is invalid for this system and for the way he'll be using this computer.
The reason I recommend the Rosewill Capstone 450-M is it's a very high-quality modular PSU that totally crushes the CX500 and only costs $69.99 shipped. This PSU would last him "forever", as I believe I've already shown several times now.
If someone wants to bring up PSU degradation, I covered that already too. With enthusiast-class PSUs like the 450-M, it's not an issue at all. It's only a problem with lower quality PSUs. The quality of the components inside like the capacitors is so high that you'd have to be folding 24/7 for a couple of years in order to have any hope of even putting a dent the PSU's capacity due to aging.
If you don't mind a quality non-modular PSU that would require you to use the power cable from your previous PSU, then here's the 400W Antec NEO ECO for only $39.99 shipped:
It is a SeaSonic S12II inside.