Pro and fast answer required: how many Watts PSU will my system need?

[solarcquence]

I ordered a PC with these components and since I ordered it with Chieftech 600W PSU first, a little later I realised that wasn't a good choice and I now need to pick something better fast. Corsair VX450W is not too expensive and I like reviews and I would take it, only I'm not sure if it will be enough or I need 550W version. Or maybe something else not too expensive but similar quality? How about Gigabyte GE-P450P-C2? I have other choices too.

My system will be:

Intel Core I5 750
Gigabyte GA-P55A-UD3
Kingston DDR3 4GB
Samsung F3 500 GB HDD
MSI GT220 DDR2 Heatpipe
Simple DVD-RW
Nexus Clodius case
Zalman Flex CPU Cooler

I will also have PCI audio card and maybe will have up to 3 HDD in the future and maybe better VGA but I don't think I'll ever use 2 video cards and this PC is not for gaming, it's for Photoshop and graphic design only.

Thank you.

 

[delluser1]

You don't think that the Corsair 450 would be enough but wonder if the Gigabyte 450 would.
The Corsair can provide 3 more amps of power on the 12v rail, where the power is needed.
Unless you plan on a much higher end card and some heavy overclocking the Corsair 450 would do, I'd go with the 550 just for more headroom.

 

[jsc]

If the 450 G'byte is enough, the Corsair 400CX is also. They both have 30 amp 12 volt rails.

 

[13thmonkey]

Should be plenty, my Q9550 and 8800GTX used 300W peak, so a good quality 450 will be ok. However upgrading to 550W would be useful to give you a bit more headroom.