IBM launched its latest version of the IBM Z mainframe, the IBM z14 (z14), in September 2017. Based on all the advanced technical information, the IMS Performance team was excited to get their hands on this awesome machine. Since receiving the box, our team has been busy evaluating IMS performance on z14. We had 2 goals:
- Compare the performance of various IMS workloads running on the z14, including native applications such as COBOL/PL/I, as well as modern Java applications
- Publish a white paper explaining all the z14 performance improvements compared to its predecessor, the IBM z13 (z13)
The great combination of IMS 14 and z14 demonstrated performance improvements in all tested IMS code paths. IMS applications may benefit from many new features of the z14, including high performance processors, increased cache density, improved micro architecture, pauseless garbage collection, and second generation Simultaneous Multithreading (SMT).
One of the key z14 differentiators is the ability to encrypt data with minimal impact to performance when compared with the z13. We were keen to see how this feature fares in our IMS workload testing. We tested encrypting various supported IMS datasets, including Full Function VSAM databases, IMS OLDS, z/OS logger offload datasets, CQS SRDS and CQS checkpoint datasets. Our testing results demonstrated that the encryption overhead was significantly reduced on the z14 as compared to the z13. While there will always be some cost to encrypting data, z14 has emerged to be an extremely cost-effective solution to encrypt your data without making any application changes or heavily impacting CPU overhead.
The results of our IBM internal testing, which was done in a controlled laboratory environment, demonstrated the following z14 performance improvements over z13:
Performance improvements in the range of 3-21% for the various IMS workloads:
Approximately four times less encryption cost on the z14 as compared to the z13 for specific IMS workloads:
You can find further details on IMS 14 and z14 performance, including workloads and environment configurations, here.
In a nutshell, the z14 and IMS 14 offer state of the art encryption technology while retaining the famed performance benefits to allow our customers to expand their capabilities confidently.