When CyberPunk 2077 launched, it required AVX, a set of CPU instructions not found on any classic Mac Pro. Clever hackers had removed the requirement for steam and, GOG distributions. In a show of how fast things move, while writing this blog post version, 1.05 was released, which now removes AVX requirements from CyberPunk, effectively mooting the tutorial I had planned.
CyberPunk 2077 surprisingly runs fine on older hardware long as you have a beefy GPU. Due to limited macOS support for GPUs, the best GPUs supported by both macOS and Windows 10 for gaming currently are the Radeon VII and 5700 Xt, neither of which pack enough muscle to play at 4k with maximum settings. That said, nearly maxed 1440p is totally achievable (I only disabled motion blur as, for some reason, I find it bothers my eyes and lowered texture filtering and volumetric shading too high). If you lower settings further, higher resolutions are available. Like most games, the limiting factor is the GPU. Users with lesser GPUs like RX580 should expect acceptable framerates 1080p with reduced settings.
Step 1: Update your GPU drivers to the latest
AMD released specifically for CyberPunk 2077 a GPU update, version 20.12.1 (or greater). These can be downloaded via the Windows AMD Control panel or via their website.
If you don't, the game will likily crash after the create a character screen.
Step 2: Make sure you're running CyberPunk 1.05 or later
Next, make sure you've updated before starting. Otherwise, the game will generally crash after the prologue.
In my limited testing, the game runs perfectly fine on my Mac Pro without any (additional) glitches.