This capability is based on the flexibility of the design and structure, which allows concurrent hardware installation and Licensed Internal Code (LIC) control over the configuration. 

Subcapacity models provide for a CP capacity increase in two dimensions that can be used together to deliver configuration granularity. The first dimension is by adding CPs to the configuration, and the second dimension is by changing the capacity setting of the CPs currently installed to a higher MCI. In addition, a capacity increase can be delivered by increasing the CP capacity setting, and at the same time decreasing the number of active CPs. 

Consideration:  A z14 ZR1 Max4 has a maximum of four PUs available, so it can concurrently be upgraded to models A04 - Z04. If a capacity setting with more than four CPs is required or the combination of CPs and specialty engines exceeds four, a non-concurrent upgrade to a CPC drawer Max12 feature (FC 0637)$^{a}$ is required. 

a. If more specialty engines are needed, Max24 or Max30 feature might be required. 

z14 ZR1 servers allow the concurrent and nondisruptive addition of processors to a running logical partition (LPAR). As a result, you can have a flexible infrastructure in which you can add capacity without pre-planning. This function is supported by z/OS, z/VM, and z/VSE. This addition is made by using one of the following methods: 

GLYPH<SM590000> With planning ahead for the future need of extra processors. Reserved processors can be specified in the LPAR’s profile. When the extra processors are installed, the number of active processors for that LPAR can be increased without the need for a partition reactivation and initial program load (IPL). 

GLYPH<SM590000> Another (easier) way is to enable the dynamic addition of processors through the z/OS LOADxx member. Set the DYNCPADD  parameter in member LOADxx to ENABLE . z14 ZR1 servers support dynamic processor addition in the same way that the z14 M0x, z13, z13s, zEC12, and zBC12 support it. The operating system must be z/OS V1R10 or later. 

Another function concerns the system assist processor (SAP). When more SAPs are concurrently added to the configuration, the SAP-to-channel affinity is dynamically remapped on all SAPs on the system to rebalance the I/O configuration. 

## 8.2.1 Upgrades 

z14 ZR1 servers feature the following machine type and model, CPC drawer features, and model capacity identifiers: 

GLYPH<SM590000> Machine type and model 3907- ZR1 

The 3907-ZR1 is available in the following CPC drawer features: 

– Feature Max4 (one PU SCM installed) can have a maximum of 4 PUs for client characterization. 

– Feature Max12 (two PU SCMs) can have a maximum of 12 PUs 

– Feature Max24 (four PU SCMs) can have a maximum of 24 PUs 

– Feature Max30 (four PU SCMs) can have a maximum of 30 PUs 

GLYPH<SM590000> Model capacity identifiers (MCI) are A01 to Z06$^{1}$. The MCI described how many CPs are characterized (01 - 06) and the capacity setting (A to Z) of the CPs). 

