HD 7570 has 624 GFLOP/s. (
http://en.wikipedia.org/wiki/Comparison_of_AMD_graphics_processing_units)
I'd estimate you may get up to 85 MH/s with it mining SHA-256 based coins (eg. bitcoin) or roughly 85 KH/s with it mining scrypt based coins (eg. litecoins).
This is not a lot. You won't make much from mining with it. As it's OEM it might have overheating problems, especially with scrypt mining because of the high load on the memory (many OEM cards have no memory cooling).
Proceed with caution. I'd monitor core temps very closely with GPU-Z and memory chip temps with an IR thermometer or your finger if your feeling lucky.