What is FreeSync?
FreeSync is a technology used by your computer graphics driver to sync the frame rate of your monitor to your graphics card.
Without syncing the frame rate it is possible that your graphics card produces frames twice as fast as your monitor can display them which creates the effect of 'screen tearing' when two or more frames are attempting to be displayed at the same time.
Screen Tearing Example
By syncing the frame rates of your monitor and graphics card the effect of screen tearing is reduced during gameplay.
Troubleshooting
Check Your Graphics Card Is Compatible
Confirm that your graphics card is capable of using FreeSync by looking up the specifications of your card from the manufactures website.
Check Your Monitor Is Compatible
Confirm that your monitor is capable of using FreeSync by looking up the specifications of your monitor from the manufactures website.
Update Your Monitor's Settings
Open the setting menu on your monitor by pressing the 'Menu' button, and check FreeSync is activated.
All monitors are different, refer to your monitor's user guide for specific instructions.
Update Drivers
Make sure the correct drivers are installed for your graphics card and you are running the latest stable driver version for your card.
Download and install the AMD Radeon software to make sure your card has access to the latest driver updates.
Check That FreeSync Is Enabled In AMD Settings
In the AMD Radeon settings go to, 'Display' and check that 'Radeon FreeSync' is turned On.
If your GPU or monitor do not support FreeSync you will not be able to turn this function on.
Check Your Monitor's Inputs Are Compatible With FreeSync
Some of your monitor's inputs may not support FreeSync. Verify in the specification of your monitor which ports are ideal for your intended set-up.
For example, a Display port may have a high refresh rate than an HDMI port for FreeSync.