karash5050 :
I can't answer yes or no to 530W being enough, but I can say that to be on the safe side, you should upgrade to 850W or thereabouts. Plenty of juice and you'll definitely have no problems.
Any of these guys make good units:
Seasonic - superb
Corsair
Antec - generally very good
Silverstone
Thermaltake - some good, some not so good
[strike]Coolermaster[/strike]
PC Power & Cooling
You do not need an 850 watt PSU for a single video card.
I do not have any figures on power consumption of a -448, but since it is close to the GTX570 in performace, those figures should work. I'd estimate power consumption of the card around the low side of 240 watts (20 amps at 12 volts). I'd estimate total system power consumption at around 350 watts.
That estimate is based on actual measurements of one of my systems. One of my systems has an OC'd Q9550, 4 GB RAM, a GTX260 - a card with less power requirements to yours, a Gigabyte EP45-UD3P motherboard, 3 hard drives and an optical, and a Soundblaster card all powered by a Corsair 750TX.
Running 3 instances of Prime95 to load the CPU and 3DMark06 to load the GPU, it pulls 375 watts from the wall as measured by my Kill-a-Watt meter. Figuring 80% PSU efficiency, the system pulls 300 watts from the PSU.
You did not specify what your PSU was, but a
good 530 watt PSU would do. I would, however, use a good 600 - 650 watt PSU to power a system with a ti-448 in it.