So I'm looking to buy a BFG 7800GS video card but it requires a 400W PSU and I only have the 250W PSU that the Dim 4400 came with.

 

I'm wondering if that vid card will work with the PSU that I have at the moment.

 

Edit: Forgot to mention that i might buy a Leadtek 7800GS instead but not sure which one to choose yet.