System performance can be affected by the EXCPVR or IOSDRIVR options of the INITIAL IOMODE command. The INITIAL IOMODE command sets the input and output mode that TDP uses for channel communication with the database.
TDP performance can be constrained by the EXCP option since it limits I/O buffers to 24 bit storage, so fewer buffers are likely available for transferring data between TDP and the database.