Will i notice much differnce in my new graphics card?

my evga 8600 gts 256mb has been overheatin lately, 55c idle 75-90c in game with case open so i just ordered a galaxy 9600gt 512mb oc, wondering what kind of difference i should expect to see, and what temps i should expect to see idle/load. dell case so only only 1 back exaust fan, its a inspiron 530/531 case, amd athlon 64 x2 4000+ cpu, 4gigs ram, power supply is a purepower 500 by thermaltake.

this is card i ordered, http://www.tigerdirect.com/applica [...] CatId=1826

this is card i got, http://www.tigerdirect.com/applica [...] CatId=1560

i got the 9600 for only $60 shipped on diff site

You should overclock your cpu first thing...you will see big increases in games like L4D....

dell could make a decent amount of money selling bios that aren't OC locked to people with locked bios

tried both, neither worked with my motherboard.
Manufacturer : Dell Inc. (Dell)
Product : 0RY206

no money for that right now might do that later, will i still notice any difference or just barely?

left for dead, cs 1.6, killing floor, team fortress 2, garrys mod, and when left 4 dead 2 and call of duty modern warfare 2 come out

You actually have to set the pll manually in either clockgen or setfsb before it will work ...try googling your pc brand and product....or board info/name....

Use Setfsb...

I personally had the 4000 x2. Overclocked it by 200 mhz and it made a pretty good difference. But it was still way slow for alot of games from even 2 years ago. Personally I upgrade to a 6000 x2 at 3 ghz and it was night and day. I hear about hte 4000's making it up to 2.7 quite often. I think your new card will help some, but the cpu will definitely hold you back and that may be about as far a you can go gpu wise, and see tangible returns. I have not had much luck oc'ing my dell (laptop) so far so I wish you luck, I'm sure there is a way somehow.