Power reqs for 939/PCI-E?

I'm reading a review for a motherboard (Chaintech nForce4 Socket 939) I'm buying as an upgrade. They end up by saying that most people will end up having to buy a new power supply if they are upgrading. I have a 350W now, how much will I really need? In addition, I'm getting a 6600 GT and 1 GB of Corsair XMS memory. I'll be running a SB Live card, one hard drive, and a couple of ROM drives. Will I really need to upgrade the power supply?

it helps to know the make/model of the PSU you have now. Your system won't draw too much power but it is really about the +12v rail, and the quality of the PSU you have. Also, if you intend to overclock, you will also be placing stress on the PSU.

It would also help to know what cpu you intend to run, as the it is the dominant power-consumer in most systems.

ok, thanks for the replies. The cpu is a athlon 64 3000, and the current PSU is a Enermax EG365P-VE. I don't intend to get into overclocking on this computer. I'm just trying to cheaply upgrade it so I can play games on it at a second location. Here is my newegg list:

CHAINTECH VNF4/Ultra Socket 939 NVIDIA nForce4 Ultra ATX AMD Motherboard - Retail
Model #: VNF4/Ultra
Item #: N82E16813152049
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$73.00 $73.00

Video Cards
Qty. Product Description Unit Price Savings Total Price
1 Leadtek PX6600GT TDH Geforce 6600GT 128MB GDDR3 PCI Express x16 Video Card - Retail
Model #: PX6600GT TDH
Item #: N82E16814122201
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$149.00 $149.00

Memory - System
Qty. Product Description Unit Price Savings Total Price
1 CORSAIR XMS 1GB (2 x 512MB) 184-Pin DDR SDRAM DDR 400 (PC 3200) Unbuffered Dual Channel Kit System Memory Model TWINX1024-3200C2PT - Retail
Model #: TWINX1024-3200C2PT
Item #: N82E16820145450
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$117.00 $117.00

Processors
Qty. Product Description Unit Price Savings Total Price
1 AMD Athlon 64 3000+ Venice 1GHz FSB Socket 939 Processor Model ADA3000BPBOX - Retail
Model #: ADA3000BPBOX
Item #: N82E16819103537
$139.00 $139.00

It is possible the enermax will run the system, I'd probably at least try it.

If you decide to get a new supply any quality ATX12V2.X should do the job, like an Antec TPII480 or Fortron AX-500A. The Fortron is my first choice for this sort of application.

I had this one in my cart already just in case. Should I just go ahead and buy it?

Thermaltake TR2 W0070 ATX 430W Power Supply $39.99

nvm, I went ahead and just bought it. I may want to upgrade to another hard drive in the future anyway.

Hmm, I would of thought the Enermax would be plenty of power for your system. It's got a nice 12v rail and it's made by a reliable company. In fact, I think the Thermaltake will give you less power thant he Enermax.