FYI the "auto undervolt" in the driver is pretty useless. If this is your first attempt to undervolt your 5700XT, then I can recommend the OCCT method. If you follow these instructions you'll be done in about 5-10 minutes.
Download OCCT and run the 3D test with shader complexity 8 to load up your GPU:
View attachment 160611
Then open the AMD driver and:
- Set Tuning Control to manual
- Enable the GPU Tuning slider
- Enable the advanced control slider
- Set the frequency to 1910. That's the median speed a Strix will average anyway (varies a bit depending on application/game) but you won't be losing much performance, if any, at 1910.
- Start voltage at 1100mv and hit apply, check OCCT for errors.
- Keep reducing by 25mv, until you see errors
- Add 75mv to whatever value gave you errors, apply, and then save it as a preset.
- Run some games, make sure it doesn't crash.
View attachment 160619
If you're a nerd like the rest of us, run a repeatable benchmark with your new undervolt and then again with the defaults to see if you've lost any performance. If you have, you can either live with it for the tradeoff in lower temps and noise, or you can set the frequency up to, say, 1950 and try again.
For what it's worth, my reference card will generate errors in OCCT at 1850MHz and 945mv. I would expect you can run 1910MHz at under 1000mv but it's the silicon lottery; your mileage may vary!