1080p 144Hz
Radeon RX 580
If you are looking for an affordable GPU to play competitive games at 1080p at high-refresh rates then the RX 480/580 is still the best deal around. You might have to lower settings in more demanding games if you want to hit 144Hz, but for the majority of games the 580 will get the job done. It will do 1440p and even 4K decently in many less demanding titles thanks to the 8GBs of VRAM.
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