how reliable is eXtreme power supply calculator?

[Tip3r]

http://www.extreme.outervision.com/PSUEngine

I'm upgrading my CPU and GFX card and I wanted to know if my power supply is good enough. the calculator at corsair's website has limited options and it recommends me a 450 watt PSU.
The link above however says 330 watts are needed.
I currently have a 380 watt PSU. should I keep it?

 

[StraightPipe]

Please list parts you will be using.

 

[theAnimal]

What PSU do you have?

 

[yh125d]

As far as psu calcs go, its more accurate than most

Tell us what the 12v rails on your PSU are, as well as its age and model number, and your system specs and we can give you a more accurate recommendation.

 

[Tip3r]

Here are the specifications of my power supply.
It's about 3 years old.

my mobo is a Asus P5B Deluxe WiFi.
I have 2 sony DVD RW connected to it and a SATA 250GB samsung HDD.
I also have a sony floppy drive.
everything else inside the case will be changing pretty soon.
this is what I already have:
XFX GeForce 7900GT
3GB Kingstn DDR2-667
Pentium D 945

This is what I'll probably be getting:
GeForce GTX 260
8GB DDR2-800 (don't have a specific brand or model in mind yet)
E8500 or Q6700 processor (I was going to get some opinion about this in the CPU forum later on, people have had problems with 45nm CPUs on P5B boards although it seems that the newer BIOS has pretty much solved most of those problems. Q6700 is the best 65nm CPU (I think)).

If you think I need a new power supply, how much power would I need?

EDIT:sorry about the link. fixed it.

 

[yh125d]

I'd get a new PSU. I couldn't read the link (too small text) but I found this one http://namayeshgah.com/goods/S...ducts/17671-BigPic.jpg

~26A on 12v, no active PFC, only 72-75% efficiency... Yeah you want a new one

A good ~500w PSU would be fine for that setup, I'd recommend the Antec BP550, Corsair 550VX, or PCP&C 500w