(03-06-2014, 01:50 PM)Xenosaga Wrote: Actually, a good 400W PSU will handle almost any regular, sensible gaming system (e.g. a 4570K + Radeon R9 280X) for years to come.
Seriously, people tend to massively overestimate a system's power usage and buy either overpriced PSUs that yield no advantage whatsoever or $25 750W PSUs from ebay which equivalate timebombs. If you do not have any definite plans on going SLI/Crossfire, there's no reason to go over 550W.
What about the electrical efficiency. Most power units runs with best "electrical efficiency" when having a workload of 70 to 80 percent.
Your vendor should be able to tell you the specs of your power unit.
So you have to look over the electrical loads and sum up the consumption.
(video card, cpu,...) The total cunsumption should be the same amount as 70/80 percent of the power unit output.
If your system has at a max workload a consumption off e.g. 300 watt (which is realistic looking at your components) with an powerunit which has 80 percent electrical efficency, the total consumption will be 375 watt. (300/0,8=375)
A power unit of 450 watt should do, but with an bigger power unit you have a better electrical efficiency.
Depends on what you are doing with the pc.
If you play resource costing games all day long, most time of the week, you shoud go for a bigger powerunit than 450 watt.
You're just playing frome time to time and work with the pc? Then 450w is sufficient.
