A HD 2xxx can handle more bots than your graphic card? you paid 20$ 6 years ago right?...
lika macatho says, buy a new one...every hd 6xxx or hd 7xxx does its job more than perfect.
i picked up an fx 8350 for 175$ canadian on sale, runs up to 10 instances of wow just fine, OC'ed on air with their own overclocking tool to 4.5ghz. I love it!
edit: https://www.cpubenchmark.net/cpu_value_available.html this list is also quite helpful, I enjoy looking at craigslist ads as well to find second hand builds that you can get for cheap and upgrade easily and make just botting cases
14 bots with GTX 660 gfx card on low settings and 16 gigs of RAM. The bots required a little under 8 gigs of RAM. That's without over clocking it to 3.9