Refresh Existing Gaming Machine

Hi Guys!

I currently have a gaming machine I built about 18 months ago. It is feeling a bit old (I know first world problems) and I want to do a refresh. Here are the current specs

Intel i5-2500K

GA-Z77-DS3H 

8gb DDR3 1600mhz 

500gb WD HDD with Windows 8.1

64gb SSD with OSX on it. I have since bought a MBA so this will be a purely a windows machine now.

Sapphire Radeon HD 6850 Graphics Card

550W 80+ Bronze PS

Generic Case.

What do you guys think? Keep the system and upgrade the video card? If so, what should I move up to?

Budget is $500.

Thanks!

For $500, you could pick up a new motherboard and heatsink as well as a GPU.

http://pcpartpicker.com/p/2hBYv