HP XP P9000 for Compatible High Perf FICON Connectivity Software - Manual (Page 70)

If the priority mode or the bind mode is set, the cache size is calculated assuming that one slot has
the following values.
•
For open-systems volumes:
For OPEN-V, one slot is 264 KB (512 LBAs). ◦
◦ For other than OPEN-V, one slot is 66 KB (128 LBAs).
•
For mainframe (3390) volumes:
◦ One slot is 66 KB (128 LBAs).
Calculating cache size for open systems
70 Estimating cache size