hi i am buying a psu to upgrade my pc . i don't know the model number .all i know is it is 600w and from cooler master.should i buy this or go for any other company.Are cooler master power supply 80%+ certified.
It should be fine. Corsair HX620 is a great choice if you want to upgrade to a 80+ PSU, but the drawback is that the Corsair PSUs are very noisy. Thermaltake ToughPower Grand is 80+ Gold and very quiet as other thermlatake PSUs, but don't expect it to be cheap.
The general rule of thumb is a high quality 500 to 550 watt power supply with sufficient current (amps) on the 12 volt rail(s) can easily power a system with any single video card made.
Corsair, PC Power & Cooling, and Seasonsic are some of the brands that have a reputation for high quality power supplies that consistently earn high marks in technical reviews. They are reliable, stable, and come with a 5 year warranty. Lately we've been seeing a few other brands offering some high quality units.