when z/IP exploitation was first introduced in R17, the biggest concern was that a user-code (ADS or DC-COBOL) heavy CV would not fare as well with z/IIP exploitation enabled, and perhaps would even suffer under z/IIP exploitation
our worst fears were confirmed in one CV (62) where TCB usage increased 10% due to z/iip restrictions and the massive number of swaps (at times over 10K per TRANSACTION
over the IDMS releases, due to the modification (fixes) and z/IIP policy changes, I can report that during a trial period I can report the following:
wthout zip
50K tasks/day
0.020 total cpu/task (all TCB)
no swaps (obviously)
with zip:
same 50K tasks/day
0.022 total cpu/task
0.005 TCB cpu/task
0.017 SRB cpu/task (ziip)
2K+ swaps/ transaction
every CV is different, and every day is different fror a given CV
but I am confident in saying that in OUR environment, z/IIP exploitation has led to a definite and measurable billable cpu reduction in ALL our environments