Regarding Performance Issue of Premiere Pro 2020

Your CPU right now is in no-man's land. There is absolutely no GPU that's currently available that's an ideal performance match to your CPU, while every single GPU in your price range that's available new is no better than a sideways-grade from your current RX 580. And your RX 580 is already a bit overqualified for your CPU to begin with. What's more, none of the Nvidia GPUs that are priced anywhere near your price point have more than 4 GB of VRAM (the cheapest 8 GB Nvidia card costs triple your stated maximum budget limit). And to top it off (or bottom it out), there is a big gap in performance between the GeForce GTX 1650 and the next cheaper Nvidia GPU, the GT 1030 (which you would not want due to the complete absence of a hardware H.264 or HEVC encoder). Your CPU falls right in between the 1030 and the 1650, in terms of a relative performance match.

That said, you might want to try a GeForce GTX 1650 (non-Super) for that system - but only if you're planning to keep that 7-year-old system for years to come (as any upgraded CPUs in the near future will be overqualified for that GPU that I'm suggesting), and you're suffering through AMD's buggy GPU drivers. Otherwise, you'd be better off saving up for a completely new CPU platform with a new CPU, motherboard and RAM as future versions of Adobe Creative Cloud (and by extension, Premiere Pro) might not even install at all on a system that's more than four years old at the time of that particular version's release.

And don't upgrade to a GPU that's more powerful than the one that you already have. That would have created an even bigger performance mismatch between the CPU and the GPU, making crashes and/or corruption even worse.

Moved to the Video Hardware forum.