Best under 400 watts

There is no such thing as a gaming psu.

You need a psu that is strong enough to support a good graphics card for gaming.


Here is a list of psu requirements listed by evga for various graphics cards:

GTX550ti needs 400w with 24a on the 12v rails plus one 6-pin PCI-E power lead.

GTX560 needs 450w with 24a on the 12v rails plus two 6-pin PCI-E power leads.

GTX560Ti needs 500w with 30a on the 12v rails plus two 6-pin PCI-E power leads.

GTX570 needs 550w with 38a on the 12v rails plus two 6-pin PCI-E power leads.

GTX580 needs 600w with 42a on the 12v rails plus one 6-pin and one 8-pin PCI-E power lead.

GTX590 needs 700w with 50a on the 12v rails plus two 8-pin PCI-E power leads or 4 6-pin power leads.

Do not try to buy a cheap psu. It is the last place to economize.

My short list of quality psu brands would include
Seasonic, Antec, PC P&C, Corsair, and XFX.

If it is actually capable of 400W, such as a 380W Antec Earthwatts or 400W Corsair Builder, you should be able to run a HD6850 on it as long as the rest of your rig is relatively modest (e.g. not half a dozen hard drives, watercooling, and an overclocked 140W CPU; etc).

But what about ATI Radeon 5770 isnt that good for playing GTA IV on high settins and low resolution (cause i dont really care about resolution)

Post your specs inclusive of PSU brand and model until then we really cant recommend even. Some cards have problems in older boards some 400watt PSU's are more like 300watt and so on!

Ok
i found this on the side
AC Input 220-240V-,6 3A,50Hz
DC Output 400W
+3.3V 20.0A(ORG)
+12V2 W/Noise Killer Hi-Pot

The only thing that helps me out of that info is +12v2 indicates two rails probably work for the 550!

Ok
So should i get the GTX550 TI or get new 500W PSU and get GTX 260 ?
Cause i want to play GTA IV with ENB and upcoming games on medium settings or low...

Much better.

Yeah, that one's a lot better.