currently i have a g620 2gb of ram and h61 s2p motherboard i m planning to buy a vapor x hd 7770 and another 2gig of ram
how much fps will i get on bf3 ultra sleeping dogs maxed hitman absoultion most wanted 2 on 1440x900
Probably around 20 FPS in BF3 @ that resolution.
Your CPU is what you'll need to upgrade next.
Although it's good for the the money, it's not a lot of money, therefore not that good.
The video card and additionnal ram will ensure that games will be playable. Whether it's in low quality, medium or medium-high, newer titles will play well.
My opinion is that graphics details only account for about 5% of the overall experience you get with a game. If it runs smoothly is much more important.