What kind of noise reduction did you choose?
- Never ever use PRIME, because it’s designed for exclusive use of the CPU and will provide the longest possible processing times. Use HQ, DeepPIME or DeepPRIME XD instead.
Is your DPR set to use the CPU only?
- Switch the setting to either GPU or ANE, observing that the later provides best processing times but can occasionally produce colour casts like described in this post regarding PhotoLab…depending on the version of macOS used. Not sure if that effect also affects DPR though.
Which version of macOS is installed on your Mac?