How much power will I need?

[Wightpants]

I'm looking to put together a system which I will then upgrade over the next few months/year or so. I have no idea what amount of power I'll need from the PSU. Here's what I've got planned so far:

To start with:

Asus P5E3 Premium Intel X48
Intel Core 2 Duo E7200 'Wolfdale' 2.53GHz
2GB DDR2 PC2-8500C5 1066MHz
ATI Radeon HD 3850 256MB GDDR3
Seagate Barracuda 7200.10 250GB SATA-II 16MB Cache
Lian-Li PC-7A PLUS II Case

Eventually I'll add and upgrade stuff to end up with something like:

Asus P5E3 Premium Intel X48
Intel Core 2 Quad 3.xxGHz
4GB DDR3
ATI Radeon HD 3850 256MB GDDR3 - XFired with...
2xATI Radeon HD 4850/4870
Seagate Barracuda 7200.10 250GB SATA-II 16MB Cache
Seagate Barracuda 7200.11 1TB SATA-II 32MB Cache
Lian-Li PC-7A PLUS II Case


What kind of power would I need for my original setup and what for the final setup? Could I just start off with enough juice in my original setup? Or should I upgrade the PSU when I start upgrading the rest of the system?

I'd appreciate any advice,
Thanks,
Wightpants.

 

[Pneumonic]

You cant use DDR2 on a DDR3 board

In terms of power 800w ish should be plenty

 

[Wightpants]

You cant use DDR2 on a DDR3 board

Really!? I thought they were compatible! Good job you noticed then.

Thanks for the info,
Wightpants.

 

[RJC]

Is this the board you want:

http://www.overclockers.co.uk/showproduct.php?prodid=MB-262-AS&groupid=701&catid=5&subcat=1050&name=Asus%20P5E3%20Premium/Wifi@N%20Intel%20X48%20(Socket%20775)%20PCI-Express%20DDR3%20Motherboard

 

[Wightpants]

That's the one, RJC.

 

[p4radox]

I'd also recommend about 800W ish. Something from the likes of:

Thermaltake
Corsair
Enermax
PC Power and Cooling.

 

[RJC]

Memory will be fine, read Pneumonic post wrong.

 

[DarkMatter]

im hoping to run that on a 520W PSU... well something very similar. I think anythign over 700W will be perfectly fine