Bottleneck?? help

I'm not very familiar with the Core2Quad's, but I would think that the CPU will be able to keep up with either of those GPU's as neither are very demanding. 4gb of ram for seems acceptable for that system as well. However, given the cheap prices of ram lately I would recommend to upgrade to 8gb.

You may want to check how much better the 640 is vs the 9800. According to Tom's Hierarchy Charts, it would be a pretty lateral "upgrade". Maybe you want to consider a 650 to make it more worthwhile? That may start to chip at the CPU though. Link - http://www.tomshardware.com/reviews/gaming-graphics-card-review,3107-7.html

If you did want to upgrade the ram, you would need to make sure you were running a 64-bit version of windows to take advantage of the extra ram, as 32-bit windows only sees up to 4gb of ram.

I wouldn't go thru the expense of upgrading to 8gb of ram on that system, ddr2 isn't cheap, the money is better saved for a new build.

No, it won't bottleneck the card, but if i were you i'd get the 7750 it's at a similar price of the 640 gt.

True enough. Wasn't thinking that was running DDR2.

I wouldn't consider upgrading your system to much. Better to go with a new build. If you want to upgrade graphics I'd go 7700 series or Nvidia x40,x50 series. They can be found ~ $100 and give pretty good performance.

YOu can get a new GPU and things should be better. Something like a GTX 650 or 550TI would be good. I went from a 9800 to a GTX460 and saw a great improvement. I was using a Phenom 2 triple core at the time and I do not feel like I was getting much of a CPU bottleneck. I think your quadcore is pretty similar to what I have (you may want to overclock it if possible).

However, as others have said I don't think a 640 is enough of an upgrade to be worth your while.

totally disagree with others, your 2.4ghz core 2 quad is bottlenecking your current video card. I would upgrad/overclock the cpu first. and the 640 isnt much of an upgrade and the 620 is a downgrade.