Hello, @annimagical
What is the cause of the crash? Is there a specific game or app that could trigger the green screen? Or did you change a hardware component recently?
With the above in mind, I don't think underclocking (or overclocking) will fix the issue. Instead, and in general, the first thing you want to do is figure out whether it's hardware (i.e. faulty PCI slot, cable(s), RAM/MB compatibility, etc.) or software issue (driver, OS, game, app, etc.).
A simple way to figure it out is by simply removing and then reinstalling your GPU (while keeping the same driver). Do the same with your RAM sticks.
On the software side, you can reinstall the driver or revert to an older, stable, version.
Something tells me your issue has to do with memory...
Sam
Your biggest fan!
CPU: AMD Ryzen 7 5800X3D GPU: AMD Radeon RX 6800XT