The 5670 is an entry level gaming card at best. It will run any game out there right now adequately on lower graphics settings, but you won't be maxing out much of anything aside from older games, and maybe Call of Duty if you play at a low resolution like 720p.
If you are looking for a card that doesn't consume a lot of power, the Radeon HD 7750 is a much better choice. The 7750 is considerably faster than the 5670. If you want other recommendations, tell us what games you want to play, what resolution you want to play them at, and other specs about your system, CPU, motherboard, power supply.
i would like 2 play max payne3,alan wake,battlefild3,fifa13 etc so what card should i prefer with 450watt psu and a budget of $120??????I WANT TO PLAY ALL UPCOMING GAMES AT MID-MAX SETTING AT RESOLUTION OF 1366x768
The best card you are going to get for $120 right now is the Radeon HD 7750. The HD 7770 is better, but it starts at $130. Either card will run those games fine at your resolution, but you are unlikely to max out Max Payne 3 and Battlefield 3 with your budget. Those two games can be demanding. If you can afford the extra ten dollars to get the 7770, it would definitely be worth it, especially for MP3 and BF3. If not, the 7750 will perform adequately at your resolution, you will just have to turn some settings down to medium or high to get playable framerates.
You may have to try and overclock your CPU to get the full potential out of the 7770, 2.2GHz is rather slow. A 7750 won't be held back as much if you can't overclock. As for the power supply, 450 Watts is enough if it is a good quality unit. Can you give me a brand and model number of the power supply?
Well if you don't want to overclock, your options are to put up with the CPU bottleneck, or upgrade to a new CPU. Problem is, you are on a very outdated platform, so unless you want to spend way too much money on obsolete technology, you would have to get a new motherboard and RAM as well as a CPU, so basically a new system.
You could get the 7770 now, and see how it performs, and consider moving it to a newer system in the future when finances permit a new build.
Getting a Core i3 would be better in the long run, it gives you an upgrade path to quad core CPUs, and the current i3s are much faster than even the best Core 2 Duo. The only drawback to moving up to an i3 is that you would need a new motherboard and probably new RAM as well as a new CPU.
You can get a faster Core 2 Duo, but I wouldn't pay more than $80 for one at this point. Problem is that the faster Core 2s tend to go for more than that now. You also have to check the CPU support for your motherboard, your motherboard may not support every Core 2 Duo out there, limiting your options for an upgrade.