>...I am experiencing a slow restore from backupset...

Please... When posting questions regarding restorals, please include
the command line(s) or GUI operation you are using, as the particulars
of the operation may make a huge difference, as IBM article swg21156683
illustrates in a Unix environment, using wildcards (and, by extrapolation,
in any environment where a restoral is being performed via multiple
individual commands).
Seeing the manner in which the restoral was requested of TSM will help
us to better ponder the circumstances.  We can't promise to have the
answer solely on that basis, but it will give us a better shot at it.

   thanks,  Richard Sims