To use max XZ compression and all cores add export XZ_OPT='-T0 -9' to the end of your ~/.bashrc file. To use all cores add export XZ_OPT='-T0' to the end of your ~/.bashrc file. To use max XZ compression add export XZ_OPT='-9' to the end of your ~/.bashrc file. Then exit terminal and go back or source ~/.bashrc

Here’s a couple tips and tricks while using dd on Linux You can view the status of an on-going dd command (I always forget to run with progress or the version you’re using doesn’t have it) You will need another terminal window. Not a problem for me as I always use tmux, some people say screen it better. Find PID of dd process -> ps aux | grep -v grep | grep dd