Detailed Before-and-After Analysis of IBM z16 Upgrades

The z16 cache design marks a radical departure from previous IBM mainframes. Given the importance of efficient use of the cache subsystem to CPC performance and capacity, there has been great interest among the performance community in how z16s are performing in the ‘real world’. But there has been very little public information about actual customer experiences with these new models.

In this reprint from Cheryl Watson’s Tuning Letter 2023 No. 2, Todd Havekost provides detailed information and insights from his analysis of seven upgrades from both z14 and z15 CPCs to z16s.

From this analysis, mainframe sites interested in upgrading to a z16 will have an indication of what to expect in terms of how an upgrade to a z16 might impact their MSU consumption (and therefore, their software bills).


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