The restart issue might relate to motherboard BIOS or graphics driver. Please refer to the following instructions for resolve.
- Update the motherboard BIOS to latest version and Load Optimized default setting.
- Re-install the graphics card driver to latest version. Driver link: Windows 8.1 64bit ; Windows 10 64bit
- Make sure the power supply can provide sufficient wattage.
- Verify the graphics card with other platform.
If problem still remains, please contact your supplier to arrange further examination on the hardware.