z/OS

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The z/OS Table summarizes the z/OS base support for specific IBM z17 functions by z/OS release. The IBM z17 server supports z/OS 3.2, z/OS 3.1, z/OS 2.5, and z/OS 2.4. Functions are either supported in the base operating system (Yes or No), require a PTF (PTF), or require a Web deliverable (Web). For additional details, see the Table Notes at the end of the z/OS Table.

Note: The IBM z17 is supported on z/OS 2.4 systems with the purchase of an extended support contract for IBM Software Support Services and PTFs (see Table Notes). Earlier releases, such as z/OS V2R3, are not supported for use with an IBM z17.
Support for z17 z/OS® 2.4 z/OS 2.5 z/OS 3.1 z/OS 3.2
Base support(1,2) PTF PTF PTF PTF
IBM z17 function
Processors: The maximum number of processors that can be configured per server:
For the IBM z17 Models ME1 and ML1 (9175):
  • Up to 208 processors can be configured as CPs, zIIPs, IFLs, ICFs, or optional SAPs
  • The sum of CPs and zIIPs configured in a single z/OS LPAR cannot exceed:
    • 208 on z/OS 2.4 or later in non-SMT mode
    • 128 cores/256 threads on z/OS 2.4 or later in SMT mode
 Yes Yes Yes Yes
Processors: The maximum number of processors that can be configured per server:
For the IBM z17 Models ME2 and MER (9176):
  • Up to 82 processors can be configured as CPs, zIIPs, IFLs, ICFs, or optional SAPs
 Yes Yes Yes Yes
Two-way simultaneous multithreading (SMT) for zIIPs, IFLs, ICFs, or SAPs. Yes Yes Yes Yes
Up to 40 TB of Redundant Array of Independent Memory (RAIM) per server Yes Yes Yes Yes
Up to 16 TB per z/OS LPAR through usage of the 2 GB large frame area (LFAREA).(3) No Yes Yes Yes
Up to 4 TB per z/OS LPAR Yes Yes Yes Yes
Channel subsystems: The maximum number of channel subsystems (CSS) that can be configured per server.
For the IBM z17 Models ME1 and ML1 (9175):
  • Up to six channel subsystems
  • Four subchannel sets per CSS
  • Up to 85 LPARs
For the IBM z17 Models ME2 and MER (9176):
  • Up to three channel subsystems
  • Four subchannel sets per CSS
  • Up to 40 LPARs
 Yes Yes Yes Yes
HiperDispatch enhancements Yes Yes Yes Yes
IBM Z Integrated Accelerator for AI PTF PTF PTF PTF
Crypto Express8S toleration PTF PTF PTF PTF
Crypto Express8S support of Quantum Safe algorithms PTF PTF PTF PTF
OSA Express7S 1.2 1G/10G/25G Yes Yes Yes Yes
ICA-SR 2.0 for short-reach coupling:
  • 8 CHPIDs/port for CS5
  • For models ME1 and ML1 (9175): 48 adapters, 96 ports per CPC
  • For models ME2 and MER (9176): 24 adapters, 48 ports per CPC
 PTF PTF PTF PTF

Coupling Express3 LR 10Gb/25Gb optics for long-reach coupling:

  • 8 CHPIDs/port for CL5/CL6
  • 64 adapters, 128 ports per CPC
 PTF PTF PTF PTF
Support for 512 coupling CHPIDs, 96 physical ICA SR coupling links, and 64 ICP internal coupling channels PTF PTF PTF PTF
10 GbE and 25 GbE RoCE Express 3 SR and LR (CX6-DX) PTF PTF PTF PTF
FICON® Express32G
  • FICON Express32G LX
  • FICON Express32G SX
 Yes Yes Yes Yes
Hyperlink® Express 2.0
  • Maximum of 16 adapters / 32 ports
 Yes Yes Yes Yes
IBM Flexible Capacity for Cyber Resilience Yes Yes Yes Yes
New IBM z17 instructions (assembly language support) PTF PTF PTF PTF
CPU measurement facility (CPU MF) new extended counters PTF PTF PTF PTF
z/OS BCPii and HMC/SE enhanced security No No PTF Yes
Workload level sustainability and power consumption reporting No No PTF Yes
Workload Classification Pricing No PTF PTF Yes
Replacement capacity records for Tailored Fit Pricing for IBM Z Hardware (TFP-HW) No PTF PTF Yes
SCRT replacement capacity reporting PTF PTF PTF PTF
Integrated I/O architecture:
  • Network Express
  • Enhanced QDIO
 No PTF PTF PTF
ICSF clear key HMAC support through CPACF No PTF PTF Yes
IBM Z Deep Neural Network (zDNN) support for new NNDA instructions No PTF PTF Yes
IBM Open XL C/C++ for z/OS No Web Web Web
z/OS System Recovery Boost — Dynamic I/O Activate No No PTF Yes
z/OS System Recovery Boost — PRESCPU for transient boost zIIPs No No PTF PTF
Coupling Facility — Code level 26 (CFLEVEL 26) PTF PTF PTF Yes
Coupling Facility — Non-disruptive system-managed copy process for lock structures No PTF PTF PTF
Coupling Facility — z/OSMF Sysplex Management support for creating a CFRM CDS with 4096 structures No PTF PTF PTF
Coupling Facility — Support for 4096 structures in a single coupling facility(4) No No No PTF
Coupling Facility — Release retry index by authority enhancements(4) No No PTF PTF
z/OS ICSF support for CCA Release 8.5(4) No No PTF PTF
z/OS ICSF support for quantum-safe cryptographic support on EP11 coprocessor No No PTF PTF
Support for the IBM Spyre™ Accelerator No No PTF PTF
Simple Network Management Protocol (SNMP) support for enhanced QDIO (EQDIO) No PTF PTF PTF
25Gb Long Distance Coupling Link Adapter (CL6) PTF PTF PTF PTF
Notes:
  1. For z/OS 2.4 systems, this support requires the purchase of an extended support contract for IBM Software Support Services, plus PTFs.
  2. To obtain the base support PTFs, use the required service fix categories (FIXCATs).
    • For the IBM z17 Model ME1 , use FIXCAT value IBM.Device.Server.z17-9175.RequiredService plus the FIXCATs for earlier processors.
    • For the IBM z17 Model ME2 , use FIXCAT values IBM.Device.Server.z17-9175.RequiredService and IBM.Device.Server.z17ME2-9176.RequiredService, plus the FIXCATs for earlier processors.
    Exploitation of many functions is provided by PTFs. To obtain the PTFs for new functions, use the appropriate exploitation fix category (FIXCATs).
    • For the IBM z17 Model ME1, use the FIXCAT value IBM.Device.Server.z17-9175.Exploitation plus the FIXCATs for earlier processors.
    • For the IBM z17 Model ME2, use the FIXCAT values IBM.Device.Server.z17-9175.Exploitation and IBM.Device.Server.z17ME2-9176.Exploitation, plus the FIXCATs for earlier processors.
    • For the IBM z17 Models ME1 and ML1, use the FIXCAT value IBM.Device.Server.z17-9175.RecommendedService.
    Recommended service PTFs are fixes that are recommended by IBM Support. To obtain the PTFs for recommended service, use the appropriate fix category (FIXCATs), as follows:
    • For the IBM z17 Model ME1, use the following FIXCAT value IBM.Device.Server.z17-9175.RecommendedService plus the FIXCATs for earlier processors.
    • For the IBM z17 Model ME2, use the following FIXCAT values IBM.Device.Server.z17-9175.RecommendedService and IBM.Device.Server.z17ME2-9176.RecommendedService plus the FIXCATs for earlier processors.
  3. Starting with z/OS 2.5, z/OS supports an architectural limit of 16 terabytes (TB) of processor storage per LPAR. If more than 4 terabytes (4 TB) is defined to a z/OS LPAR, all memory beyond 4 TB is taken from the 2 GB large frame area. For information about the large frame area and the associated LFAREA parameter, see z/OS MVS Initialization and Tuning Reference. Earlier supported releases of z/OS support up to 4 TB of processor storage per LPAR.
  4. Some features require a firmware bundle for machine types 9175/9176 to be delivered August 2026. These features are indicated by note (4) in the table above.