When configured, STP creates a Coordinated Timing Network (CTN) that is used for maintaining CPCs in sync with an ETS. 

When in DPM mode, a CPC can be configured as a Single Server CTN . Through STP, time synchronization information is provided to the operating systems that is running in the partitions (LPARs) on the CPC. 

Operating system support is required for the use of the STP feature. Linux on Z and z/VM support time synchronization by using STP. 

STP tip:  STP provides timing information to all partitions in a CPC. If the CPC uses STP, all active partitions can maintain time synchronization to an external source without requiring external timing source access (through a network connection). 

Moreover, the IBM Z CPC is equipped with Pulse Per Second input to increase time synchronization accuracy from 100 ms (standard NTP accuracy) to 10 microseconds when a time source (NTP server) is used that also includes a Pulse Per Second output (PPS). 

For more information, see the following publications: 

GLYPH<SM590000> Server Time Protocol Planning Guide , SG24-7280 

GLYPH<SM590000> Server Time Protocol Implementation Guide , SG24-7281 

GLYPH<SM590000> Server Time Protocol Recovery Guide , SG24-7380 

## Processor considerations 

The following processor characterization types can be configured and used for customer workload  on a CPC that is managed by using DPM: 

GLYPH<SM590000> Central Processor (CP) 

GLYPH<SM590000> Integrated Facility for Linux (IFL) 

Important:  Simultaneous Multi-Threading (SMT) is not supported on CPs. As of this writing, only IFLs support SMT. 

The following processor types cannot  be configured when the CPC is managed by using DPM: 

## 16.1.4 Enabling DPM 

GLYPH<SM590000> IBM Z Integrated Information Processor (zIIP) 

GLYPH<SM590000> Integrated Coupling Facility (ICF) 

Enabling DPM is a disruptive action. The selection of DPM mode of operation is done by using a SE task that is named Enable Dynamic Partition Manager under the CPC Configuration menu, as shown in Figure 16-2 on page 392. 

For more information about DPM enabling, see IBM 3907 Installation Manual,  GC28-6973. 

Note:  During the machine installation$^{a}$ or in preparation for DPM (later), the IBM SSR connects the two OSA Express 1000BASE-T cables to the Ethernet Top of Rack (management) switches in the designated ports. 

a. The DPM mode of operation setting is normally performed at machine installation time by the service support representative (SSR). 

