Best psu need to run smoothly pc?

It's not a PSU that I would buy or use in my system, but you already have it. It's got 17amps on the 12v, so it should be sufficient to power a 5770.

Yea like I said it will power it but IDK beyond that you start asking too much of a cheap power supply and you are asking for trouble.

Just watch this video too see what happens when you demand too much from a cheap power supply.
http://corsair.com/cinema/movie.aspx?id=622747

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. A high quality 700 to 750 watt power supply with sufficient current (amps) on the +12 volt rail(s) can power a system with two video cards operating in dual mode. There are a few exceptions like the new ATI Radeon HD 5XXX series cards which use less power due to their energy efficiency.

A high quality 500 to 550 watt psu will have a +12 volt rail rated at 40 amps. A high quality 700 to 750 watt psu will have a +12 volt rail rated at 60 amps.

In addition the power supply should be at least 80+ Bronze certified for energy efficiency. There are some models available which have achieved 80+ Silver and 80+ Gold Certifications.

Before purchasing a new psu you will need to decide whether you will eventually have a pc with one or two video cards.

Corsair and Seasonic are two 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. Some of the newer models come with a 7 year warranty. Lately we've been seeing a few other brands offering some high quality units. One example would be the Antec Earthwatts and Antec TruePower New models which are a major improvement over Antec’s older psu’s like the Basiq models.