Vista - I'm looking at a hd 4850 or maybe a 4830 & my PSU

I'm in the process of giving my system an almost complete overhaul starting with the motherboard & some new ram. I already have a good case with a good PSU thats only a few months old being used on my current setup which i'm planning to still use in my new setup.

I have an Antec NSK2400 which came with a Antec SU380 earthwatts 380watt PSU. It has dual 12V rails at 16 amps each.
Antec NSK2400 / Fusion Media PC Case | silentpcreview.com PSU specs.

I'm thinking of getting an ati hd4850 when I next get some cash together which recommends a 450watt PSU.
Looking at the specs of cheaper 500watt PSU's shows they give off less amps per rail than my antec 380watt PSU? seems odd to me.

From what perspective are ati recommending a 450 watt PSU, are they assuming the worst case senario of Joe public with a cheap 450watt PSU onboard just to play it safe maybe?

Does any one think my current Antec PSU could cut it with a 4850 onboard?
from what i found out appears to be a rebranded Seasonic Super Silencer 400watt PSU
Antec SU380 power supply (in NSK2400 case) | silentpcreview.com

Is the 500 watt you're looking at a reputable brand, such as Corsair, Thermaltake, PC Power and Cooling?

Branded PSU's such as a 450 watt one will be more expensive than a 500 watt, 600 or watt or even 700 watts (700 watts are being sold for about £20-£30 on ebay, but no brand) because they're generally a lot better quality in build and performance.

I'm not sure what "quality" of PSU it is when it says "recommended 450 watt", but it's always best to get a proper PSU. It is probably the only component in a computer you musn't cut corners on. I learnt that a few years ago when I bought a no branded PSU as a replacement and blue sparks started flying out the back of my PC.

My current PSU is a branded one it's an Antic earthwatts 80 plus rated, which from what i found out appears to be a rebranded Seasonic Super Silencer 400watt PSU?
Antec SU380 power supply (in NSK2400 case) | silentpcreview.com

I'm just wondering if it would be able to handle a 4850 given it outputs more amps per rail than i cheap 500watt PSU?

hm...... i would just go ahead and get a branded 600 watt psu like a cosair

My PSU is a branded one and i'm thinking it might just maybe cut the mustard, so to speak? looking at the Amps per rail with a limited understanding of things mostly thanks to google? but i'm not really that confident enough to no for sure in my understanding of things when it comes to PSU's and other hardware?

well i would still try to get a higher wattage psu...... 600 would be good and you can get one for about 50 or 60

It's alot of cash when you add a new supply to the mix aswell. My current PSU is basically still new and i am running a hd2600pro of it at present with no issues & thats a recommended 400watt PSU. The 2600pro tops out at about 95 watts max. The 4850 tops in at 110 watts max.

eh well ok you can try it.....
if it fries your psu shouldn't hurt anything

The only thing that will happen if you try it is your PC will shut down whenever the graphic card gets under too much load for the PSU to handle. If that keeps happening, then you'll know

Might as well give it a shot then, with some stress testing like 3dmark, prime & trying out a few demanding games. If it does not cut the mustard i'll guess i'll find out pretty quickly that way. It's not like it's going to harm anything to try it.