To take advantage of the benefits of AMD FreeSync technology, users will require:
A monitor compatible with DisplayPort Adaptive-Sync.
A compatible AMD Radeon GPU with a DisplayPort connection.
A compatible AMD Catalyst graphics driver.
The driver can be downloaded from the AMD driver download below:
To enable Freesync on compatible Viewsonic Monitor
Open the OSD by pressing the number “1” button on the monitor.
Go to Advanced Image Adjust settings and then enable AMD Freesync option by selecting it and pressing the number 2 button.