core 2 quad core

Hi I recently upgrade my CPU to Core-2 Quad 9550@2.83 GHZ. I have installed two 4gb DDR3 ram (total=4*2=8 Gb). The problem is my ram running at speed of 500MHZ (Please look below photos).I think it should run at 1333 MHZ speed but i don't know much about it that's why all Bios settings are by...