what powersupply do I need?

I'm gettnig a p4 3ghz... I have 2 hard drives (one of them is SATA which uses more power I suppose) and 2 drives: cd and dvd... umm and 2 fan cases (just a mid-tower case)

is a 480W power supply too much or is it good for this system?

You could probably get away with ALOT less wattage, but you would limit yourself to future upgrades.

I have a 430WATT PSU that runs the following:

Athlonx XP 2100+
Shuttle ak31a mobo
Geforce 4 Ti4600
Turtle Beach Santa Cruz Sound Card
NIC
Approx 7 fans total
2X 80GB 7200 RPM Maxtor HD
1X 120GB 7200 RPM Maxtor HD
DVD+RW/CD+RW Drive
2X 256MB DDR pc2100

Runs perfectly fine and I'm sure I could add a few more things (in fact, I plan on doing so) so I doubt you'll have ANY problems powering what you want with a 480WATT PSU.

heh cool I think I'll go with this then :)

OK... more naivety! ;)

The watts isn't the only part of the equation!!! Make sure the PSU has more than a 16AMP on the +12 volt string.

AMD's recommended minimum AMP is 18 and I think Pentiums is 12/14... so any lower, and you could have some very strange problems in the future.

I'm running a 550Watt 24AMP PSU, which owns my last PSU. Most standard 'QTEC' branded PSUs are not to AMD's required standard. Just be careful which one u choose. It is the most important part of the PC! ;)

I had heard that most AMD compatible power supplies are good. The one I'm getting supports AMD too, even though my comp isn't AMD... I hope it's good, it's only $50 hehe
I know the Anatec True Power is the best, but it's way too expensive (uuh about $120). Otherwise I would get that, hehe

dont try to slink by with your power supply

if u have extra watts its all the better

I'm thinking of buying the 480 watt Antec True power tomorrow... this is supposed to be the best, but its very costy:( If I dont see anything with a lower price I'll go with this

Antec are very good quality.

It may be costly, but it's money well spent! :p