You don't need anything close to 8 cores. Most games these days don't even utilize the 4 cores of mainstream desktop processors.
Anything above 4 cores should be relegated to server style applications, intense Video Editing / Photoshop work. I have a 6 core processor in my main machine. But I'm a "Power User" I have a small windows 2012 r2 domain running in Virtualbox all the time on there, as well as using the computer for games.
I currently run 6 VMs
2 x 2012R2 DC
2 x 2012R2 File Servers
1 x 2012R2 WSUS
1 x Sophos UTM
All of that is running in "The Background" while I do everything else as well.
Intel 980x running OCed at 4.25Ghz, 24Gb RAM, and an AMD R9 290x pushing games out max everything (Except AA) at 1440p