Graphics card to go with i3-2120

[Kadano]

Hello!
My current system is: ASRock Z68 Pro3 Gen3 (has PCIe 3.0 support)
Intel i3-2120
No GPU, I use IGP at the moment.
I used to have a Sapphire 6870 back when I had the Intel G530, but I sold it after I stopped playing with Diablo 3. I mainly upgraded to i3 for faster deinterlacing and x264 encoding, and because I got a good deal on it (83€).
Now from what I've read hear so far, I get the impression my i3 will be enough, but for which resolution? I want to play Melee and Brawl (focus on Melee) at constant 60 fps. My screen is 1080p, so I want to achieve this resolution if possible. I'd rather go for lower resolution than lower fps.
If my i3 is not good enough for this (assuming GPU is not the bottleneck), which of these cpus will be? i5-3350P (4x3.1 GHz, no igp), 2500k, 3570k

And now my main question. Which graphic card should I get? A used 6870 would be pretty cheap (90€), so if it will be enough for 1080p, I'd like to go with that. How is it compared to 560 (similar price) and 560ti (a bit more expensive)?

[LordVador]

6870 will do the job just fine. You'll get almost the same performance with 560 Ti.

For the processor: 3570k is the best choice. But you'll need a Z77 MoBo

[Kadano]

Thanks, I'll get the 6870.

But is the update necessary or might 2120 be enough?
Also, why will I need z77? I've already updated my z68 bios to the version that supports Ivy Bridge.

[NaturalViolence]

You need a graphics card for dolphin. Even at 1x IR your IGP will not be sufficient for a lot of games.

[Kadano]

All I wrote about cpu upgrading was meant assuming I'd get a 6870 card (or better) too.

[NaturalViolence]

In that case it depends on the game. For heavier games yes.

[Kadano]

But Super Smash Bros Melee and Brawl aren't heavier games, or are they?

[NaturalViolence]

No. They will probably run fine.

[Kadano]

Even at 1080p? That will be awesome!

[NaturalViolence]

CPU performance has no effect on the reduction in performance (if any) that you get from increasing the internal resolution. It merely sets a baseline performance level. GPU performance effects the reduction in performance (if any) that you get from increasing the internal resolution