Disable Steam overlay/streaming, FRAPS, Mumble, ShadowPlay, or any FPS counter/HW info overlay.
-Updating all drivers
-Disable VSYNC in Borderless window with tesselation OFF.
(Go to My documents-Rockstar-GTAV and modify settings file.)
-Change DX11 to DX10.1 in settings file
-Disable your main graphic car and re-enable it when game started
-Underclock your card with MSI Afterburner
-Delete new Nvidia or Radeon driver and install previous dri