512mb his hd 3650 agp 4x/8x

Usually it's around 20-30 amps but im not sure about AGP 8X

I ran that card on a cheapo 300watt PSU, but not for long. After a bit I switched over to my pretty good 500watt.

meaning it should work when a power supply have 19A each on the dual +12V?

Yeah it should work, mine had 18amps on the 12v, it was a real cheapo PSU.

its ur 18amps are in a single +12V rail? or dual?

Your power supply will run it just fine. A hamster could power it

Btw, does it matter if my board doesn't have the 4 pin ATX12V socket, since it is a ATX model, not an ATX12V, does that means it would only use one +12V instead of 2?

that 4pin ATX 12v thing is for your CPU.

yeah but my mobo doesn't have that socket for the CPU, since it is an old ATX one, so does it mean it's only use one +12V rail?

It just means your processor doesn't get direct power from you PSU but across your board instead. Nothing to worry about.

I am getting an Antec Truepower 2.0 550W, since my current psu can't run my graphic properly, so yeah... it goes very loud, and freeze at around 20 mins, reboot, freeze at windows xp blue loading bar, try safe mode freezes again, and notice the card get really hot.

Thats a good PSU, try running your case open air, by keeping the side panel off, you'll need to clean the dust out more often but it can be cooler.

how often do i need to clean the psu? do you mean by cleaning the dust from the inside of the PSU?