Best video card on a 300w power supply

5570 might run on a 300 watt psu but I dont know where you're going to find one for 80.00. you might want to upgrade that psu with your 80.00. If it runs it, it will be taping it pretty good and if your psu dies.....

Thx for your answer. How much should i expect to pay for a new power supply and a similar video card to a 5570 from newegg.ca?

you won't find anything that would be much of an improvement over your 4200 that will run on a 300watt PSU

I ordered a 5450 card to try on a old P4 dell with a 300 watt psu, and even with that card they want 400 watts officially

can you do a hybid crossfire with that mobo?

Why are you upgrading your Video card?

A decent PSU would cost you between 50 and 80.00. Try for a name brand, Corsair, Antec, Thermaltake, OCZ. Rosewills have proven reliable for me, but I am a budget user and havent run huge power hungry cards or crossfired. 4850 is about my speed, now 5770 or 5850 max. I would try for a min 550, but try to afford a 650 or more. Lok at amps and rails. Two rails with 25A each is good. 4 rails with 20A each is better. Amps provide the grunt in the watts. I look at it like torque. AND, I was wrong on the 5570, you can get one for about 70.00 on new egg. Sorry bro. Bad intel. They call for a min 400 watt psu, so 550 is enough.

5570
4650
5670
GT 220
GT 240
low power version (59w) 9600GT

All of these run on 300w and are less than $80
I have the same issue as you have done weeks of research and this is what I got.
I prefer 5570 or GT 240 which are equal but the 5570 is the best way to go.

AND you have way more RAM than this sort of computer needs, I suggest you sell your RAM, you only need like 4GB, and buy a new PSU and a good card like the 5770.- the best budget gaming card.