Is it safe to install a GTX 660 with a 500w PSU?

What's the brand of the psu in question ?

Running it at close to 100% all the time will make the fan and itself die alot quicker.
So I think you should get 600w, I too got one for my GTX 660.

Scorpian

It's not enough. 22A on 12V rail is too little for that card - you'd be pushing it too close. I'd suggest getting a cheap but quality power supply unit from reputable brands, such as Antec/Corsair/XFX or Seasonic. For example, Antec VP-450 or Corsair CX 430.



Watts mean nothing.

Where do you live?

Sunius is right in fact .As much as the power (Watts) requirement matters, the current requirement, measured in Amps is as important if not even more important. This is especially true if you have an or several dedicated video card(s). As a general rule of thumb, you are aiming for the highest number on the 12V line.I recommend this one if your on a tight budget.
Antec Neo Eco 520C
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
Seasonic made. 40 amps 12V power. $55 and 3 yr warranty

I have 600w and written on it 12v1 30a and 12v2 22a how do i know which one is v1 and v2 am getting this card too so i wNna know

What is the brand and model of this power supply if it does not say anywhere it's most likely a unreliable lemon.

Its HEC i got it for 65$