How do i tweak my 7870's settings?

I know nvidia has there own control panel thing. But i cant seem to find the one for my 7870?

most manufacturers have an overclocking app, MSI has afterburner, I don't know the names of any other ones but I know Asus has one also just check the website.

AMD has the Catalyst Control Center, in the taskbar. If it's not in the taskbar, go to AMD's website and download the latest driver.