Identifying server requirements

z/OS® V2R4 is supported on the following IBM Z® servers:

• IBM® z15™ (z15)
• IBM z14™ (z14)
• IBM z14® ZR1
• IBM z13® (z13®)
• IBM z13s®™ (z13s)
• IBM zEnterprise® EC12 (zEC12)
• IBM zEnterprise BC12 (zBC12)

z/OS uses particular machine facilities on these servers, depending on the z/OS release. Table 1 lists the machine facilities that are required for each release of z/OS. A program that runs on a particular z/OS release can use the facilities that are identified for that release. These facilities cannot be disabled on the z/OS system, for example, by using the LOADxx MACHMIG statement (as described in z/OS MVS Initialization and Tuning Reference).

Though additional machine facilities might be available on a server, it does not mean that z/OS supports those facilities. Usage of any machine facilities that are not listed in Table 1 should be investigated by your program developer to ensure that the facility is supported by the z/OS release, server level, and operating environments, such as zPDT® and z/VM®, if z/OS is run as a guest. For your reference, Table 1 includes earlier releases of z/OS to help show a progression of required machine facilities over time.

Table 1. Minimum server levels and machine facilities that are required for z/OS

z/OS release level	Minimum required z/VM level for that z/OS release	Minimum server level	Exploitable machine facilities
z/OS V2R1	z/VM 6.2, at z/OS V2R1 general availability. Increased to z/VM 6.4 on 31 December 2016, due to end of service date.	Z9 EC or z9® BC	Base z/Architecture® mode, plus the following extensions (by STFLE bit): Bit Machine Facility 3 DAT-enhancement facility 1. 6 ASN-and-LX-reuse facility. 7 Store-facility-list-extended facility. 19 Long-displacement facility has high performance. 20 HFP multiply-and-add/subtract facility. 21 Extended-immediate facility. 22 Extended-translation facility 3. 23 HFP-unnormalized-extensions facility. 24 ETF2-enhancement facility. 25 Store-clock-fast facility. 27 Move-with-optional-specifications facility. 30 ETF3-enhancement facility. 31 Extract-CPU-time facility. 32 Compare-and-swap-and-store facility. 41 Floating-point-support-enhancement facility. 42 Decimal-floating-point facility. 44 PFPO facility, which provides the instruction PERFORM-FLOATING-POINT OPERATION.
z/OS V2R2	z/VM 6.3, at z/OS V2R2 general availability. Increased to z/VM 6.4 on 31 December 2017, due to end of service date.	Z10 EC or z10 BC	All previously required machine facilities, plus the following extensions (by STFLE bit): Bit Machine Facility 26 Parsing-enhancement facility. 33 Compare-and-swap facility 2. 34 General-instructions-extension facility. 35 Execute-extensions facility. 43 Decimal-floating-point facility.
z/OS V2R3	z/VM 6.3, at z/OS V2R3 general availability. Increased to z/VM 6.4 on 31 December 2017, due to end of service date.	zEC12 or zBC12	All previously required machine facilities, plus the following extensions (by STFLE bit): Bit Machine Facility 37 Floating-point extension facility. 45 Distinct-operands, fast-BCR-serialization, and other facilities. 48 Decimal floating point zones conversion facility. 49 Execution-hint, load-and-trap, and processor-assist facilities. 52 Interlocked-access facility. 75 Access-exception-fetch/store-indication facility.
z/OS V2R4	z/VM 6.4, at z/OS V2R4 general availability.	zEC12 or zBC12	All previously required machine facilities, plus the following extensions (by STFLE bit): Bit Machine Facility 50 Constrained transactional-execution facility. 73 Transactional-execution (TX) facility.

Processor configurations by z/OS release

The IBM z15™ family of mainframes includes the following hardware models:

• Model T01 (machine type 8561), with five feature codes to represent the processor capacity. The feature codes are Max34, Max71, Max108, Max145, and Max190 with (respectively) 34, 71, 108, 145, and 190. This system is configurable as a one-to-four 19-inch frame system.
• Model T02 (machine type 8562), with five CPC size features (one or two drawers). The system is configurable as a 19-inch frame system.

For the z15 Model T01 (machine type 8561), the z/OS releases V2R4, V2R3, V2R2, and V2R1 support up to 190 processors configurable as general-purpose processors (CPs), zIIPs, IFLs, ICFs, or optional SAPs. The sum of CPs and zIIPs configured in a single z/OS LPAR cannot exceed:

• 190 on z/OS V2R1 or later in non-SMT mode
• 128 on z/OS V2R1 or later in SMT mode.

For the IBM z15 Model T02 (machine type 8562), the z/OS releases V2R4, V2R3, V2R2, and V2R1 support up to 65 processors configurable as CPs, zIIPs, IFLs, ICFs, or optional SAPs. The sum of CPs and zIIPs configured in a single z/OS LPAR cannot exceed 65 on z/OS V2R1 or later (in either SMT or non-SMT mode).

For IBM z14 models M01 through M05, the z/OS release V2R4, V2R3, V2R2, and V2R1 support up to 170 processors configurable as CPs, zIIPs, IFLs, ICFs, or optional SAPs. The sum of CPs and zIIPs configured in a single z/OS LPAR cannot exceed:

• 170 on z/OS V2R1 or later in non-SMT mode
• 128 on z/OS V2R1 or later in SMT mode.

For the IBM z14 Model ZR1, z/OS V2R4, z/OS V2R3, z/OS V2R2, and z/OS V2R1 support up to 30 processors configurable as CPs, zIIPs, IFLs, ICFs, or optional SAPs. The sum of CPs and zIIPs configured in a single z/OS LPAR cannot exceed 30 on z/OS V2R1 or later (in either SMT or non-SMT mode).

For the z13 and z13s™ servers, z/OS V2R4, z/OS V2R3, z/OS V2R2, and z/OS V2R1 (with PTFs) support the following maximum number of processors per LPAR:

• Up to 141 processors per LPAR, if the partition is IPLed in non-simultaneous multi-threading (non-SMT) mode.
• Up to 213 threads per LPAR, if the partition is IPLed in simultaneous multi-threading (SMT) mode.

For other IBM servers, z/OS supports:

• Up to 101 processors per LPAR on the zEC12 running z/OS V2R1 or later.

Notes:

1. The total number of processors that are defined in a z/OS LPAR is the sum of general-purpose processors (CPs), zIIPs, IFLs, ICFs, or optional SAPs.
2. The z15™, z14™, z14 ZR1, z13, and z13s servers do not support the IBM zEnterprise Application Assist Processor (zAAP).
3. Coupling Facility levels (CFLEVELs) have hardware and software requirements. For more information, see Coupling Facility Level (CFLEVEL) Considerations.