Despite being released eight years ago, Grand Theft Auto V can still use help with performance. It’s just that sort of game. You can use the in-built upscaler (running the game at a lower resolution than your monitor's native resolution then upscaling to the correct size) to do so, but the image quality definitely suffers from it. Thankfully, a better method has appeared in the form of AMD's DLSS-alike, FidelityFx Super Resolution (or FSR). It's been ported over to GTA V by a fan, and when you compare the two side-by-side AMD’s image quality definitely wins out.
Redditor “NarutoUA1337” pulled this off by porting the FSR files from another unmentioned game. In the video, you can see a number of modes running with each implementation. 0.5x (running at half-res and scaling up) is “performance mode”, and 0.75x (running at three-quarter resolution and scaling up) is “quality mode”. It does take a few seconds for your eyes to adjust, but there is a noticeably sharper image in FSR mode.
This screenshot comparison really shows off the difference if you want to compare the two at your leisure. The ground textures are noticeably less blurry using FSR upscale. Quite a win.
FSR does drop a couple of frames, but as you’re already claiming a significant frame rate boost overall by upscaling, there’s really no reason to settle for the game’s native version, unless you’re worried about being banned in multiplayer. This hasn’t been tested in GTA Online, so if you want to be cautious it’s best to not install it on that for now. Others will try, no doubt.
You can download the mod here.