Graphics card help

[arsingh1]

Hello guys,
My config :-

ASUS P5G41T-M LX Motherboard
Intel Core 2 Duo E4400 @ 2.00GHz
Corsair DDR3 4 GB RAM
Antec VP450P power supply
Seagate Barracuda 1 TB HDD Internal
Hitachi 160gb internal

My Budget around 4k.
Please suggest me a graphics card to play games like Assassins creed 3 & running CAD/CAM soft wares Like CATIA, PRO-E, ANSYS, considering the fact that my processor is of previous generation.

i'M getting previous generation XFX NVIDIA GeForce 9800 GTX+ 512MB DDR3 256-bit XFX NVIDIA GeForce 9800 GTX+ 512MB DDR3 256-bit @ RS 4k . Should i buy this or go for nvidia 520, 430.
Plus Should i add another stick of RAM of 4 gb will it help.
Thanks..

 

[topgear]

^^ I think 9800GTX+ ain't good for the PSu you have - get a HD6670 1GB GDDR5 @ ~5.5k - 4GB ram is enough for gaming with the cpu you have.

 

[thetechfreak]

donot geta nvidia 9xxx card. atleast a minimun of HD 5670 rrcommended

 

[arsingh1]

but HD 6670 & 5670 both are Pci x16 2.0 but my MB is x16 1.0. I know 2.1 is backword compatible with 1.0 cards, but will there be any considerable performance. drop.
also in both 6670 & 5670 it is mentioned that they need crossfire ready mobo, but my mobo is not crossfire ready.

 

[the_conqueror]

^^ You won't notice any difference when you'll switch the HD 5670 from PCIe x16 2.0 slot to 1.0. But remember, get the ddr5 version of HD 5670. Stay away from ddr3 version.

 

[topgear]

but HD 6670 & 5670 both are Pci x16 2.0 but my MB is x16 1.0. I know 2.1 is backword compatible with 1.0 cards, but will there be any considerable performance. drop.
also in both 6670 & 5670 it is mentioned that they need crossfire ready mobo, but my mobo is not crossfire ready.

those cards are CF ready but that does not mean you need to have a CF ready mobo to use any of those gfx cards - your mobo is just fine for both gfx cards.