Questions about SLI and Future-Proofing

[EmptyFlame]

I'm a long time reader of [H], but this is my first post on the forums, so go easy on me if this has been answered somewhere else.

I'm currently putting together a new system for the fall semester that is going to have to last me for atleast 2-3 years for financial reasons. I have a couple important questions about PSUs that I wanted to ask the only reader base I would trust.

The current spec list is as follows (copy and paste):

- Antec P180 Case
- ASUS A8N-SLI Premium
- BFG GeForce 7800 GTX
- Antec TRUEPOWERII 550 Watt
- Either AMD Athlon 64 3800+ (Venice) or AMD Athlon X2 4400+
- Corsair Value Select 512MBx2 DDR PC-3200 (CAS 2.5)
- Samsung Black 1.44MB 3.5inch Floppy
- Hitachi 160GB T7k250 SATAII Hard Drive
- NEC 16X DVD+/-R DL Drive ND-3540A
- Creative Labs Sound Blaster Audigy2 ZS

I'm a college student, so price is always a big factor when picking out parts AND in the future. What I mean is if I buy a 550w PSU as opposed to a 400w and I'm trying to live on very little a month, I would assume it's going to hike my electric bill when I run the computer, much less if I leave it on all the time.

What I have picked out currently is an Antec 550w 2.0 for about $115 (found here). Because of budget reasons, I would like to ask if I would be able to get away with a lesser PSU (like a 400w or 480w) and still be safe down the line if I chose to put in a second card for SLI (slim chance, but I would like to have the option open to me).

Any advice or suggestions are certainly welcome and thank you in advance. Thoughts?

[EDIT]: I included the full current spec list so that you might get a better idea on what the system power needs will be.

 

[[Spectre]]

Ok please post the entire config as it all draws power from the power supply so it is all relevant.

 

[EmptyFlame]

Done. Also to note, I'm not really an overclocker / modder either (if that effects anything).

 

[[Spectre]]

Done. Also to note, I'm not really an overclocker / modder either (if that effects anything).

Ok the 550w Antec should do you fine even with the added 7800. Now a misconception you have in the post. The 550w won't cost you more by default as it only puts out as much power as you are using at any given time....meaning it isn't always producing 550w. Now as a system this one is probably more electrically demanding than your current so it may cost you more because of that...but honestly the difference shouldn't be very noticeable.

 

[EmptyFlame]

Excellent! So the system does not draw the constant 550w, but only what is needed for the system? Sounds like a plan. Thank you!