That depends on how fast you need the refresh rate to be. Currently, OLED displays can't match the refresh rates of the best IPS and VA gaming monitors at any given resolution. So while the Evnia 42M2N8900 can refresh at 138Hz the Acer Predator X32FP, another 4K gaming monitor, can refresh at 165Hz. IPS and VA displays are also capable of higher whole-screen brightness levels though OLED screens counter that with higher (in effect, infinite) contrast ratios thanks to the zero black levels they can generate.