Originally Posted by stevea
I generally agree with your design/selection criteria - but let me pick nits.
For heavy virtualization the vt-I/O instruction set might be useful, for crypto you might want the txt feature. Otherwise your i3 sounds great.
I personally don't need graphics performance, and perhaps you do. Your Nvidia 550TI at idle reportedly draws 139 watts and at load draws 248 watts
so the idea that you are saving much with a 65w vs 95w cpu is a dubious choice.
A modern 65W intel 2core system can idle well below 50 watts (excludng PSU losses) and will probably peak ~100W. But in addition you have the 248W vid load leading to a ~350W peak load (and ~190W at idle). So your 450W PSU is right-sized
and that saves a lot of power. Do note that all these high efficiency bronze/silver/gold PSU have good efficiency at ~80-100% of rated load, but the efficiency falls off badly at low loads. When you system (inboard of the PS) is idling along at 200W, the PSU maybe losing another 150W !! So your 4fans + big heat sink is justified. Make sure that vid card gets plenty of air-flow.
Assuming you need/want that sort of power hungry vid card - then the overall parts selection looks pretty clean - no silliness like 1000W PSUs.
If I was going to optimize that system I'd measure power usage and see if a 350W PSU wouldn't work.
That source for the graphics power draw gives "watts at socket", i.e. for the whole machine, not just the graphics card.
I have one of those cards (GTX550Ti) and my machine is hooked up to a power meter. At idle, my machine draws only ~10W more than with the little GeForce G210 (which supposedly only had a maximum draw of ~30W and an idle of ~9W). My whole machine idles at 90w (that's a Phenom II X4 945 overclocked to 3.6GHz), or 75W at stock speeds/voltages, so the graphics card isn't drawing much.
Playing Skyrim at max graphics quality, my entire machine peaks at ~280W. That's the highest power draw I've seen with this machine.
These new "high efficiency" 80+ certified power supplies seem to have some advantages: at standby, with my new PSU, power draw is 1.1W, compared to 8W with my old PSU. Idle power is also down ~15% with the new PSU all other things being equal. Mine states minimum 82% efficiency at any power draw, rising to 89% at full power, and that seems to be borne out (roughly) by my power meter observations.
One might also consider the duration the power supply will be used, and whether it will be re-used in an upgraded or new machine. I still have two PSUs that are >7.5 years old, and several that are approaching 6 years. One frequently used concept in maintaining longevity of equipment is "de-rating", that is, never using it at rated capacity, but rather imposing a cap considerably below that figure from the outset. I've employed that approach for 20+ years (professionally, not just at home) and there are definite reliability advantages. Professionally, I would calculate the cost/benefit given different projections in failure rates, down time, lost productivity (or effectiveness), running cost, etc. For a home computer I simply make the decision that even one lost day due to PSU failure is easily offset by additional PSU cost (including running cost), so I tend to buy well and de-rate. I do understand that older PSUs were less efficient at lower power draw, but, professionally, in my experience, that cost is almost always outweighed by reliability gains of more robust PSUs. Of course, I'm talking about more than just desktop computers, but the concept is equally applicable there in many usage scenarios. Personally, I'm heavily biased toward reliability, but others may prefer to minimise capital and running costs and take performance "on faith".
IIRC, I've had 3 PSU failures (at home) over about 10+ years or so, but that was for a small population of machines, not just one. In my professional experience, the most failure-prone electronic item is indeed the PSU, so I would tend to buy quality where possible.