HD 6670 would do just fine. A little bit bottlenecked unless you overclock your CPU, but fine.

Would it perform well with recent games like dota 2, diablo 3 ?

This machine will work good but don't expect "max" setting in 1080p with that video card... i'd rather go with the 6770 (had a 5750 and in 1280X1024 in WOW maxed out no problem) but the 6670 is less powerfull than the 5750...
For the little difference in price (at my local resseller it's 15-20$) you have a 2 times more powerfull card

Info about the cars:
6670 vs 5750
http://www.hwcompare.com/10884/radeon-hd-5750-1gb-vs-radeon-hd-6670-oem-1gb/

6770 vs 5750
http://www.hwcompare.com/5706/radeon-hd-5750-1gb-vs-radeon-hd-6770-1gb/

6770 vs 6670
http://www.hwcompare.com/10858/radeon-hd-6670-oem-1gb-vs-radeon-hd-6770-1gb/

in pass mark 6770 scores 1749pts and the 6670 1188pts
For reference the GTX550ti scores 1886 and cost about 125$

Hope that will help you ;)

and by the way if you want to overclock a little bit, i know that the g31 chipset doesn't have the vcore adjust option but the core 2 series overclock well... my q6600 2.4ghz goes to 3.1ghz on stock voltage (345 fsb)
With your E6420 i'd expect 2.67 easily (assuming you have ddr-2 800 changing ratio to 667 to match 800 @ 333fsb) that's not a high overclock but it will boost your frame rate and with the stock voltage, temps should not be a problem ;-)

Thanks for the input, im actually going for the 7750 now from many have told me. 7750 Works better as a PCI-E 3.0 is better backwards compatible with PCI-E 1.1, and is more powerful than the 6670 and costs only about $20 more. Thank you though, and for overclocking im not really sure how to do it but i'll learn soon. THanks .

Your CPU will be a bottleneck in recent games with that 7750 card.

7750 is as strong as a HD 5770/6770 and a dual core cpu (Athlon II x2) @ 2,8 GHz (slightly higher clocked than your cpu) pushes the HD 6770 to maximum 80% GPU usage in Battlefield 3.

Yeah, but you'll see a great improvement. Much more powerfull than your 8400GS ;)

My PSU is a Optimax, Titan Power ATX-550ps . Im guessing it's a 550w psu, should this psu be fine with the 7750 ? The reason i chose the 7750 over te 5770 or the 6770 is because the 7750 is a 3.0 bus slot, a 3.0 PCI-E bus slot backward compatibility is better with a 1.1 more than a 2.1 would be for a 1.1 . That's the reason i chose the 7750 . Would you guys think it would be fine as of now ? I'm going to grab it today and i hope it'll be fine .

Your PSU is strong enough.

Where do you have that "PCI-E 3.0 is more compatible with 1.1 then 2.1 is" from?
It's first time I hear that.

Someone from another forum told me that, from experience and also reference. He says 2.1 has a lot of issues with 1.1, rather 2.0 & 3.0 are better towards compatibility with 1.1. Also i believe my motherboard msi g31m3 L V2 only has 1 bus slot for a video card meaning the 6770 wouldn't fit. To be honest i just want one of the 3 doesn't matter which one that just works fine at this point.

also, thing is my psu i supposedly not a good brand so that 550w might not turn out to be 550w. But thats what i have and have to work with for now . I just hope it'll be fine .

is msi hd6570 2gb compatible with amd ddr2 motherboard ?,, pls answer this,,

Jelius,

Short Answer: Yes.

Long Answer: As long as your motherboard has a PCI-Express slot x16 it will be fine. The version doesn't matter.

Compatibility only concerns that. The DDR2 memory on a motherboard will not in any way affect a Graphics Cards compatibility. The RAM in a Graphics card is usually GDDR5 but that has nothing to do with the motherboard memory.

It will work. and the CPU shouldn't bottleneck the graphics card seeing the 6670 is classified as an entry level graphics card. Even with DDR2, it shouldn't effect performance. I'm running a 6790 right now on DDR2 and I am getting full performance. I will have to do some testing and disable 2 of my cores to simulate a Core 2 Duo with my Phenom 2 955. Once i find the time, but the 6670 should work with passion with your Core 2 Duo