In Windows for FX 83xx Series processors it will always show 4 "Physical" cores and 8 "Logical Cores". This is normal.
I have a FX8350 and this is what Windows Task Manager shows:
![](/skins/images/642D505A1A051956CE376BACC711140C/responsive_peak/images/image_not_found.png)
This is because each CPU Physical core has 2 logical cores.
In CPU-Z is shows my processor with 8 cores and 8 threads:
![](/skins/images/642D505A1A051956CE376BACC711140C/responsive_peak/images/image_not_found.png)