Coming back to the two ‘FreeSync’ settings in the monitor OSD, they differ in the variable refresh rate range that they support. ‘Standard Engine’ supports 90 – 144Hz (90 – 119Hz via HDMI) whilst ‘Ultimate Engine’ gives a broader variable refresh rate range of 70 – 144Hz (62 – 119Hz via HDMI). We didn’t notice any adverse effects when using ‘Ultimate Engine’, so we’d suggest users simply stick to that option.