NEED HELP

hello, i just bought a radeon 7870 and im getting low fps on valve games...about the same as my previous radeon sapphire 5830 xtreme..jus with more lag/stuttering...it plays non-valve games great at max...like sleeping dogs, steam does not detect my graphics card when i try to update its drivers



-radeon 7870 powercolor pcs myst edition

http://www.newegg.com/Product/Prod [...] 6814131484

-amd phenom 965 black edition 3.4ghz

-asrock 970 extreme3 mobo

-700 watt psu

-corsair vengeance 4gb

-2tb WD HDD