Err..i dint hav time to go through forums to find a similar question so im jus gonna take the easy way..
current system specs:
 
Amd 4400X2 Athlon
Asus m2n sli deluxe
3Gb ddr2
xfx 7600gt
400W PSU
Lite on Dvd Rw
160Gb Seagate
 
 
now i'd like to upgrade to a 9600gt..is the current psu enough or do i need to bump up a bit..
i hav a tight budget nd i do not overclock GPU..
please advise

What brand is the PSU. I'd be tempted to upgrade.

i got a 9750GT OCed witha 300W PSU came with my system, works fince, system specs below. Only upgrade enless you have too. Higher watt hotter it gets, which makes the room more hotter which I hate. But if you want to be on the safe side just incase get a 500w psu they can handel up to 2 video cards and 4HDs with out a prob.

P.S. I see your mobo has SLI if you decide to use SLI you HAVE TO HAVE A MIN 500W PSU for 2 video cards. If say it in the video card's manual  it self.

We would like to know the brand and model of the PSU so we can accurately answer your question.
A quality unit would have no problems with a 9600GT.  A cheap one, or a unit that has degraded with age, may not work reliably or may croak.
A higher wattage PSU will not necessarily create more heat, unless its efficiency is low.  A very efficient 500W PSU will run much cooler than an inefficient 350W PSU.

 
It's not quite like that. For example a 750W OCZ Silencer working at 85% efficiency will produce LESS heat than a 400W PSU working at 70% efficiency. Less than half, in fact. Let's say your setup needs 300W at some point in time. The Silencer will draw 353W from the wall, you pay for 353W, 53W becomes heat (that's 15% of 353), your PC gets 300W. The smaller PSU will draw 428W, you pay for 428W (i.e. more every month than with the Silencer), 128W becomes heat (that's 30% of 428W), your PC again gets the 300W it needs. The heat is proportional to the energy it comes from, which means the bigger PSU will be much cooler - which also means less noise, longer life, etc.
 
It's not the size, it's the quality of the PSU that decides.
 
I suggest this PSU:
OCZ StealthXStream OCZ600SXS 600W
http://www.newegg.com/Product/Prod [...] 6817341010
It's pretty good quality, even if not top, and I don't think you'll find better for only $55.
 

ah did not know that (learn something new everyday), my 500w(Termaltake) puts out more heat then my 300w (dell, will never buy a dell again, dident have the money for a build) system. The 300w psu in my dell is probley higher quality then a thermaltake psu?

 
We have a common misunderstanding here. A more powerful PSU (higher wattage rating) does not, by itself, generate more heat. The wattage rating is a measure of how much power the PSU can provide, not how much it uses all the time.
 
For example, let's consider a 1000 watt PSU with 80% efficiency (easy numbers to work with). If that PSU is running at full load, it will need 1250 watts input power. That extra 250 watts gets turned into heat. If the same PSU is operating with a 400 watt load, it needs 500 watts input (100 watts turned to heat), not 600 watts. A 500 watt PSU (80% efficiency) running with a 400 watt load needs the same 500 watts from the wall. And it's much less expensive.
 
For red_star:
 
A 9600GT needs about 5 amps @ 12 volts (60 watts). A 7600GT needs about 36 watts. If you PSU provides 20 amps at 12 volts, you should be OK.
 
If your PSU is inadequate, your symptoms should be random rests/reboots under heavy CPU or graphics loads - in other words, during gameplay.
 

Yea i get it now. thx for the info

This may help http://www.atomicmpc.com.au/forums [...] c=7&t=9354 My short answer is that the 400w you have will probably be enough to run it. My long answer is that since some OEM power supplies suck and they degrade with age you should really consider upgrading to a quality badged PSU.  aevm posted a good quality budget one that would easily cover your needs.

thnx alot guys..it was really helpful