Leveraging Your z Systems Investment – Optimizing Runtimes

April 22nd, 2016

J Jeffrey Broderick
z Systems Architect

For those customers that have embraced the most recent generations of the z Systems hardware, including the zEC12, zBC12, zEC13 and z13s, evaluating how to obtain the most “horsepower” from their investments should be a top priority.

As many are aware, there has been a significant number of additional instructions built into the processors in the last two generations.  Unless you are compiling your COBOL programs with a compiler that supports those newer generations of hardware, your company’s program executables are not capable of taking full advantage of the instructions and technology built into these latest processors.

There are two primary means to take advantage of the newer chip instruction sets:

  • Enterprise COBOL at V5 or higher, along with the compiler directive of at least ARCH(10) for a z12 architecture, or ARCH(11) for z13 architecture.
  • Automatic Binary Optimizer (ABO) to optimize existing COBOL V3 and COBOL V4 load modules.

These two solutions have specific value propositions:

Automatic Binary Optimizer (ABO)

ABO allows for a very quick means to optimize entire load libraries, test, then implement those load modules for a quick return on investment and increased runtime efficiencies.  IBM’s own benchmarking showed an approximate performance increase of 15%.  This 15% should translate into reduced Monthly License Charge (MLC) fees, along with potentially shorter batch windows, improved CICS transaction performance, faster COBOL module execution, etc.   ABO converts existing Enterprise COBOL V3 and Enterprise COBOL V4 modules.  ABO also requires zOS V2.2.

Enterprise COBOL V5/V6

Enterprise COBOL V5 was Generally Available (GA) June 21, 2013.  Enterprise COBOL V6 was Generally Available (GA) March 18, 2016. Customers should be putting projects together to migrate to either Enterprise COBOL V5 (z12/z13 technology) or Enterprise COBOL V6 (if you are on a zEC13/z13s).

An Enterprise COBOL migration does involve time and resources.  There are various compatibility items that need to be considered (like VS COBOL II or OS/VS COBOL modules).  Consult the Enterprise COBOL Migration Guide (GC14-7383-00) along with other resources to appropriately plan a migration.


Some customers may choose to implement ABO for a quick performance increase, and then initiate their migration to Enterprise COBOL V5/V6.

IBM ABO optimized load modules are fully supported by the suite of IBM Problem Determination Tools, along with the Rational development tooling (Rational Developer for z Systems).  Customers should verify compatibility of any third party development tooling with their respective vendors.

Start planning now to fully exploit that z Systems investment.

For more information on z Systems products, go to www.mainline.com or call 866-490-6246.

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