Performance metrics zEDC to z15 zlib Program Flow for z/OS Software support On-chip compression introduces the following system reporting changes: The z/OS provided zlib library is statically linked into many IBM and ISV products and  remains functional. However, to get the best optimization for z15, some minor changes are  made to zlib. The current zlib and the new zlib function on z14 and earlier servers and z15 hardware. It  functions with or without the z15 z/OS PTFs on z14 and earlier servers. Support of the On-Chip Compression function is compatible with zEDC support and is  available in z/OS V2R1 or later for data compression and decompression. Support for data  recovery (decompression) in the case that zEDC or On-Chip Compression not available;  however, it is provided through software in z/OS V2R2, and V2R1 with the appropriate  program temporary fixes (PTFs).  Software decompression is slow and can involve considerable processor resources.  Therefore, it is not recommended for production environments. A specific fix category that is named  IBM.Function.zEDC  identifies the fixes that enable or use  the zEDC and On-Chip Compression function. z/OS guests that run under z/VM V6.4 with PTFs and later can use the zEDC Express feature  and z15 On-Chip Compression. For more information, see the Enhancements to z/VM 6.4 page of the IBM Systems website. IBM 31-bit and 64-bit SDK for z/OS Java Technology Edition, Version 7 Release 1 (5655-W43  and 5655-W44) (IBM SDK 7 for z/OS Java) now provides use of the zEDC Express feature  and Shared Memory Communications-Remote Direct Memory Access (SMC-R), which is  used by the 10GbE RoCE Express feature. For more information about how to implement and use the IBM Z compression features, see  Reduce Storage Occupancy and Increase Operations Efficiency with IBM zEnterprise Data  Compression , SG24-8259 . 506  IBM z15 (8561) Technical Guide GLYPH<SM590000> No RMF PCIE reporting for zEDC GLYPH<SM590000> Synchronous executions are not recorded (just an instruction invocation) GLYPH<SM590000> Asynchronous executions are recorded: – SMF30 information is captured for asynchronous usage – RMF EADM reporting is enhanced (RMF 74.10) – SAP utilization is updated to  include time spent compressing and decompressing