Although we were impressed by its efficiency, we can’t recommend Rosewill Performance 650 W.

First, it couldn’t continually deliver 650 W at a room temperature between 45º C and 50º C, being a textbook example of a unit labeled at 25º C, a temperature that is impossible to be achieved inside a computer. On the good side the power supply has its protections active, so it simply shut down when it couldn’t deliver power any longer, contrary to cheap units that explode when this happens. We know that users buying this product won’t pull 650 W from it, but if I am buying a 650 W unit I want a unit that is capable of delivering its labeled power under real-world conditions.

Also noise level at +5VSB when we pulled 650 W from this unit was above the maximum allowed.

Then we have the number of SATA power connectors, too few in our opinion. We think this unit should come with five or six SATA power connectors and not only four.

And we have the price. It has a suggested retail price of USD 129, but this is just a loose reference, because we always can find Rosewill products being sold on Newegg.com at a price far lower than the manufacturer suggested retail price – sometimes half the price.

Even if Rosewill relabeled this unit as a 550 W product and lowered its price, we would still recommend OCZ StealthXstream 600 W instead. This model from OCZ costs only USD 80 (USD 60 after a mail-in rebate) and doesn’t have the flaws we listed, and is our recommendation for the user that wants a good inexpensive power supply for a mainstream PC.