多线程运行, 好像可以提高运行效率， 但是具体你的问题需要参考官方的指南。

TAGSORT
Stores only the BY variables and the observation number in temporary files. This is very useful when the disk space is limited. But, the speed of sorting is slower.

Note:  There are many other options for the PROC SORT. These information can be find in online document or help information.