I've been playing a bit of Minecraft this weekend and noticed much worse raytracing performance than previously. After a bit of investigation it looks like a regression was introduced with 1.16.220 which has substantially reduced performance, dropping from around 90+fps to 30ish, this is on an RTX 3080 with DLSS turned on at 3440x1440.
After a bit of troubleshooting it looks like its related to v-sync, changing:
Seems to fix the issue and brings performance back to a more reasonable level. If you do want to re-enable v-sync you can force it with the nVidia control panel without the issue being re-introduced.