Hi,
Most of the 10GB+ games lag in my PC except COD:MW3 (mostly in-game videos voice come first and frame follows). Can I install a 64bit 2GB DDR3 graphics card phasing out my old nVidia 210 and a 4GB RAM extra? Need Suggetion! Please give me a better details of which model in which company to opt for. Graphics card under Rs.4500-5000 price range will be preferable. And in case if I go for 1gb ATI Radeon HD6670 and ASUS nVidia 2gb GeForce GT630, which one will be better and more efficient? Give me your suggetions too.

These are my configuration,
Processor: 3.2GHz AMD Athlon II X2
RAM: Starlite 4.00 GB Single-Channel DDR3 @ 669MHz (though the box reads 4GB DDR3 PC1333)
Motherboard: ASUSTeK Computer INC. M5A78L-M LE (AM3R2)
Graphics: 512MB GeForce 210 (ASUStek Computer Inc)
OS: MS Windows 7 Home Premium 32-bit
**values provided by Piriform Speccy software
PSU is 400W

Thank you!

Just in case, what is your budget and second, what is brand of your PSU ?

Budget is 4K-5K max!
and extremely sorry fpr that PSU line..its a typing mistake, will be 450W