--parallel N to run N thread. However, it seems it only uses around 100% CPU as I observed although the command specified that N threads can be used.
The command is as follows
cat large-file | sort --parallel `nproc`
where I have 16 from
How to make sort use multiple threads to run faster?
It is possibly caused by the pipe
|: data are sent out as a stream. You can possibly make parallel take more effect by setting its buffer for
cat large-file | sort --parallel=`nproc` -S 20G
-S, --buffer-size=SIZE use SIZE for main memory buffer
as from sort manual https://www.systutorials.com/docs/linux/man/1-sort/