Assistance choosing a power supply

[gmazpule]

Hey guys, i'm currently wanting to upgrade this old HP Pavillion i have with me and i was wondering what power supply would adequately supply enough power for the upgrades. Right now my system specs are:

- OS: Windows 7 Ultimate x64 bit
- PSU: 250 W
- CPU: AMD Athlon 64 X2 4400+
- Memory/RAM: 2.00 GB Dual-Channel DDR2 @ 334MHz
- Motherboard: ECS Nettle2 (Socket M2 )
- Graphics Card: 128MB GeForce 6150SE nForce 430
- Hard Drive: 391GB Samsung SCSI Disk Device (RAID)
- Optical Drive: Elby Clonedrive SCSI CdRom Device
- Sound Card: Realtek High Definition Audio

I'm planning on upgrading the RAM to 4 GB at first, and i'll also add two additional RAM sticks in the future for a total of 8 GB (4 2 GB sticks). The link is below:

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=7017878&CatId=2261

I'm also planning on upgrading my graphics card to something along the lines of this:

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=419883

Any suggestions on how many watts the power supply should be? 250 Watts is clearly underpowered for these upgrades.

 

[rolli59]

250 watts should be enough for the HD5550 but any quality unit like this Antec EA380 would be plenty http://www.newegg.com/Product/Product.aspx?Item=N82E16817371033

 

[Uther39]

Future proof your self with some extra headroom for an extra $10, which is nothing and buy one of these,

http://www.newegg.com/Product/Product.aspx?Item=N82E16817207012

 

[gmazpule]

Thanks for the replies guys. I'll aim for one of those models.

 

[Zero_]

Actually 250W would be plenty for a HD5550, which brings me to another point, the HD5570 for just $5 more is a much better deal.

In any case, the EA380D should be plenty for even a beefier GPU upgrade. Costs just $28 an Amazon.
http://www.amazon.com/dp/B002UOR17Y?tag=banforbucga08-20&camp=213761&creative=393545&linkCode=bpl&creativeASIN=B002UOR17Y&adid=1CD7V6R7NVAB475K595G&