Revision as of 23:27, 11 April 2018

z14 is a z/Architecture-based microarchitecture designed by IBM and introduced in 2017 for their z14 processors and mainframes. The z14 microarchitecture replaced the z13.

Process Technology

z14-based microprocessors are manufactured on GlobalFoundries's 14 nm (14HP) FinFET Silicon-On-Insulator (SOI) process. The process was designed by IBM at what used to be their East Fishkill, New York fab which has since been sold to GlobalFoundries.

Release Dates

IBM z14 was announced on July 17, 2017. General availability started on September 13, 2017.

Architecture

Key changes from z13

• 14 nm process (from 22 nm)
  • 6.1B transistors (from 3.99B; 53% increase)
• Higher clock frequency (5.2 GHz from 5 GHz; 4% increase)
• Higher scalability
  • Up to 170-way multiprocessing (from 141-way)
• Core
  • Improved Operand Store Compare (OSC) prediction
  • Faster branch wakeup
  • Improved instruction delivery
  • Reduced execution latency
• Cache
  • New directory design
    • Power efficient
  • L1I$ increased to 128 KiB/core (from 96 KiB/core; 33% increase)
  • L2D$ increased to 4 MiB/core (from 2 MiB/core; 100% increase)
  • L3$ increased to 128 MiB/CP (from 64 MiB/CP; 100% increase)
  • New 672 MiB/drawer of shared L4
• TLB
  • New Translation/TLB2
    • Reduced latency
  • 4 concurrent translation
  • lookup integrated into L2 access pipe
  • 2x Larger CRSTE
  • 1.5x large PTEs
  • New 64-entry 2 GiB TLB2
• BTB
  • 1.33x larger BTB1
  • 1.33x larger BTB2
  • New Hashed Perceptron Predictor
  • New Simple Call Return Stack

• Central Processor Assist for Cryptographic Function (CPACF)
  • Dedicated co-processor for each core
  • Claims 6x faster encryption functions (vs. z13)
    • 4x Advanced Encryption Standard (AES) speedup
  • Support for True Random Number Generator
  • New support for SHA-3 standard

This list is incomplete; you can help by expanding it.

New instructions

• New SIMD instructions for COBOL and analytics applications

Overview

Mainframe

The IBM z14 mainframe comes in a number of slightly different flavors. In order to reach the highest clock speed of 5.2 GHz, the water cooled system is required, otherwise the air cooled is sufficient.

Water Cooled

Air Cooled

Every mainframe have two frames that are bolted together. Frames are built to Electronic Industries Alliance (EIA) standards and are 42U EIA frames. Viewed from the front, the right side is called Frame A while the left side is called Frame Z.

Z Frame

	At the top of the frame is an optional overhead power cabling solution. There are top exit options for fiber optic cables and other ethernet solutions such as FICON, OSA, 12x InfiniBand, 1x InfiniBand, ICA, zHyperLink Express, Coupling Express LR, and RoCE.
	There are two to four optional integrated battery features (IBFs) which serves as a local uninterrupted power source. Additionally, the IBFs provide additional power robustness functionalities such as increases power line disturbance immunity and noise reduction. The number of installed IBFs depends on the number of power regulators that are installed and is always installed in pairs.
	A configurable set of Bulk power regulators (BPRs).
	The entire bottom part of the rack consists of up to four PCIe I/O drawers, installed top-down.

A Frame

	Two support elements (SE) 1U servers.
	One optional PCIe I/O drawer.
	Two System Control Hubs (SCHs).
	Up to four CPC drawers with a minimum of at least one must be installed.
	Two radiator pumps or two Water Conditioning Units (WCUs) in the case of water cooling.

System

The IBM z14 mainframe consists of a number of drawers. A drawer is simply a cluster of processors and chipsets. Each drawer consists of two clusters of three processing units (PUs) each and a single system controller (SC) chip. A full drawer can thus have a total of six processors and a single system controller. The SC chip can links one drawer to another one for up to four drawers in the max z14 mainframe system. In a max configuration the z14 can have a total of 24 processors.

Die

Core

Below is a layout of a single physical core:

• L2 - L2I$ + L2D$
• PC + TP - Core pervasive unit (instrumentation/error collection) + Trap
• LSU - Load-store unit (+ L1D$)
• XU - Translation unit (TLB + DAT)
• ICM - Instruction cache & merge
• COP - Dedicated Co-Processor
• FXU - Fixed-point unit
• VFU - Vector and Floating point Unit
• ISU - Instruction sequence unit
• RU - Recovery unit
• IDU - Instruction decode unit
• IFB - Instruction fetch and branch prediction

Single-chip module (SCM)

IBM's z14 Single-Chip Module (SCM) consists of a multi-layer metal substrate module that includes either:

• 1x Processor Unit (PU)
• 1x System Controller (SC)

Central Processor (CP) Chip

• IBM's developed (now GlobalFoundries) 14HP Process
  • CMOS FinFET SOI
  • 17 Metal Layers
• deca-core (10 Processor Units (PUs))
• 5.2 GHz (192 ps cycle time)
• 6,100,000,000 transistors
• 14.4 miles of copper wire
• 26.5 x 27.8 mm die
  • 736.7 mm² die size
  • 18,581 power pins
  • 1,505 signal pins

System Controller (SC) Chip

• IBM's developed (now GlobalFoundries) 14HP Process
  • CMOS FinFET SOI
  • 17 Metal Layers
• 25.3 x 27.5 mm die
• 695.75 mm² die size
• 7,100,000,000 transistors
• + 2,100,000,000 cells of eDRAM (~2.1B xTors + 2.1B capacitors)
  • 672 MiB shared eDRAM L4 Cache