Should I upgrade my RX580 to a GTX 1080 or RX 5700?

Honestly, both the GTX 1080 and RX 5700 are pretty comparable. If it were me, I’d lean towards the RX 5700, especially since AMD has better driver support on Linux, particularly for ray tracing. But day-to-day performance differences are likely minimal between the two cards.

Before deciding, check the prices of the options available, including newer graphics cards like the RTX 2070, RTX 3060, or Radeon 6600. Cards older than the RTX 2000 series or RX 6000 series might miss some newer features, like mesh shaders, which could affect game performance. For instance, some games are struggling on older hardware right now.

I wouldn't go for either. They're getting outdated and won't support DX12 ultimate features. I’d recommend aiming for at least a 2060 Super or RX 6600 if possible.

The RX 5700 is generally the faster option. However, you might want to consider saving for a newer card if your budget allows, even if it means paying a bit more upfront.