There are two, perhaps three elements here.
Efficient copy utility
- Your space analysis in SAS PROC COPY.
- Your query about an efficient copy utility.
- Hiding under the covers, perhaps, is extending your space analysis to the more mainline copy utilities.
There are many relatively common copy utiliities,
Extending your space analysis to other copy utilities
IEBGENER is probably the best known copy utility. It usually works and is fairly easy to use. Efficient? Well, to be polite about it, no.
Many people think ICEGENER (or the Syncsort equivalent) are about as efficient as a copy utility can be. They are probably correct.
IEBCOPY is for partitioned data sets. Partitioned data sets, especially partitioned data sets containing load modules, can be difficult to copy. There are third party alternates to IEBCOPY that claim they are more efficient, but my sense is IEBCOPY is OK.
All the batch oriented copy utilities use the space specification in a DD statement. This leaves little room to sneak in an improvement.