To compare the performance of manipulating data in data spaces with the manipulating of data in hiperspaces, you should understand how the system "backs" these two virtual storage areas. (That is, what kind of physical storage the system uses to maintain the data in virtual storage.) The system uses the same resources to back data space virtual storage as it uses to back address space virtual storage: a combination of central and expanded storage (if available) frames, and auxiliary storage slots. The system can release low-use pages of data space storage to auxiliary storage and bring them in again when your program references those pages. The paging activity for a data space includes I/O between auxiliary storage paging devices and central storage.
The system backs hiperspace virtual storage with expanded storage (if available), and auxiliary storage when expanded storage is not available. When you create a hiperspace, the system knows that the space will not be the target of assembler instructions and therefore will not need the backing of real frames. Therefore, data movement through HSPSERV does not include I/O activity between DASD and the storage that backs the hiperspace pages. For this reason, hiperspaces are very efficient.