The z15 Model T01 system is designed in a 19-inch form factor with configuration of 1 - 4  frames that can be easily installed in any data center. The z15 Machine Type 8561 can  include 1 - 4 42U EIA (19-inch) frames, which are bolted together. The configurations can  include up to five central processor complex (CPC) drawers and up to 12 Peripheral  Component Interconnect Express+ (PCIe+) I/O drawers. The redesigned CPC drawer and I/O infrastructure also lowers power consumption, reduces  the footprint, and allows installation in virtually any data center. The z15 server is rated for  ASHRAE class A3$^{1}$ data center operating environment. The z15 server differentiates itself from previous Z server generations through the following  significant changes to the modular hardware: The power options include PDU-based power or BPA-based power. The z15 server can be  configured as a radiator (air) cooled or water cooled (that uses data center chilled water  supply) system. Only BPA-based power system can be (optionally) configured for water  cooling and with Internal Battery Feature (IBM), while a radiator (air) cooled system has  PDU-based power (no Internal Battery Feature [IBF] available for PDU-based systems).  The z15 includes the following basic hardware building blocks: 36  IBM z15 (8561) Technical Guide 1 For more information, see Chapter 2, Environmental specifications in  IBM Z 8561Installation Manual for Physical  Planning , GC28-7002. 2 KMM - Keyboard, Mouse, Monitor GLYPH<SM590000> All external cabling (power, I/O, and management) is performed at the rear of the system GLYPH<SM590000> Flexible configurations: Frame quantity is determined by the system configuration (1 - 4  frames) GLYPH<SM590000> Choice of power Intelligent Power Distribution Unit (iPDU or PDU) or Bulk Power Assembly  (BPA) GLYPH<SM590000> Feature codes that reserve slots for plan-ahead CPC drawers GLYPH<SM590000> Added internal water cooling plumbing for systems with more than three CPC drawers GLYPH<SM590000> New PCIe+ Gen3 I/O drawers (19-inch format) supporting 16 PCIe adapters 2.1 Frames and configurations GLYPH<SM590000> 19-inch 42u frame (1 - 4) GLYPH<SM590000> CPC (Processor) drawers (1 - 5) GLYPH<SM590000> PCIe+ Gen3 I/O drawers (up to 12) GLYPH<SM590000> CPC drawer Cooling Units: Radiator cooling assembly (RCA) or Water Cooling Unit  (WCU) GLYPH<SM590000> Power, with choice of: – Intelligent Power Distribution  Units (iPDU) pairs (2 - 4 per frame, depending on the  configuration). – Bulk Power Regulators (1 - 6 pairs, depending on the configuration) GLYPH<SM590000> Support Elements (two): –S i n g l e  K M $^{2}$ device (USB-C connection) – Optional extra hardware for IBM Hardware Management Appliance feature GLYPH<SM590000> 24-port 1GbE Switches (two or four, depending on the system configuration) GLYPH<SM590000> Hardware for cable management at the rear of the system