So here's what differentiates a low power supply range of quality power supply: manufacturing, sheathing cables, plugs quality, the quality of the components (which should not be "undersized" as this will the soul quickly), the quality of the fan (the life given by the manufacturer is estimated at 300,000 hours for the Straight Power E9 680W), silence design.
This power supply gets 80+ quality label gold: it is therefore sensible to consume less, heat less, be quieter, more stable, give optimum performance. This should also increase the life of the components it supplies.
Regarding the power to choose, we must take into account the different components on the PC. To give an order of ideas with a recent fairly muscular configuration, it will provide about 200 watts for the motherboard and processor, 50 Watts for a RAM, 100 to 300 Watts for the graphics card, 20 to 30 Watts for internal hard drives. A need these services please add a small safety margin.
As for me, I used two power supplies Be Quiet: Pure Power L8 530W and 680W Straight Power E9. The latter team is now my main PC. I am very satisfied with the silent operation of this power supply whose quality workmanship seems quite high game, which earned him the 80+ Gold certification.
I encourage you to equip a Straight Power E9 680W if you have a configuration for demanding applications, such as games or graphics.
