The IBM® capacity utilization and performance enhancement (CUPE) allows DFSMShsm to more fully utilize the high-capacity tapes on IBM tape drives that emulate IBM 3490 tape drives.

You can select to more fully utilize tapes on CAPACITYMODE switchable IBM 3590 tape drives that emulate IBM 3490 tape drives, or to stop filling tapes at a point that is compatible with non-CAPACITYMODE switchable IBM 3590 tape drives. The IBM 3592 Model J is also CAPACITYMODE switchable when it is emulating a 3490 tape drive. Unless there is some known compatibility issue, these drives should be run with CAPACITYMODE(EXTENDED).

You can use the 3592 Model E05 and newer tape drives only in 3590 emulation mode; never 3490. The 3592 Model J1A can operate in 3490 emulation mode only when using MEDIA5 for output.