Power7 Processor Overview - IBM BladeCenter PS700 Technical Overview And Introduction

IBM has been innovative to achieve required levels of throughput and bandwidth. Areas of
innovation for the POWER7 processor and POWER7 processor-based systems include (but
are not limited to) the following elements:
On-chip L3 cache implemented in embedded dynamic random access memory (eDRAM)
Cache hierarchy and component innovation
Advances in memory subsystem
Advances in off-chip signalling
Exploitation of long-term investment in coherence innovation
The superscalar POWER7 processor design also provides a variety of other capabilities:
Binary compatibility with the prior generation of POWER processors
Support for PowerVM virtualization capabilities, including PowerVM Live Partition Mobility
to and from POWER6 and POWER6+™ processor-based systems
Figure 2-2 shows the POWER7 processor die layout with the major areas identified:
processor cores, L2 cache, L3 cache and chip interconnection, simultaneous multiprocessing
(SMP) links, and memory controllers.
Figure 2-2 POWER7 processor architecture

2.2.1 POWER7 processor overview

The POWER7 processor chip is fabricated with the IBM 45 nm Silicon-On-Insulator (SOI)
technology using copper interconnects, and implements an on-chip L3 cache using eDRAM.
The POWER7 processor chip is 567 mm
(transistors). Eight processor cores are on the chip, each with 12 execution units, 256 KB of
L2 cache, and access to up to 32 MB of shared on-chip L3 cache.
For memory access, the POWER7 processor includes two DDR3 (Double Data Rate 3)
memory controllers, each with four memory channels. To scale effectively, the POWER7
processor uses a combination of local and global SMP links with high coherency bandwidth
and makes use of the IBM dual-scope broadcast coherence protocol.
GX+ Bridge
C1 C1 C1
Core Core Core Core
L2 L2 L2
4MB L3 4MB L3 4MB L3 4MB L3
4MB L3 4MB L3 4MB L3 4MB L3
L2 L2
L2
C1 C1 C1
Core Core Core Core
SMP
2
and is built using 1.2 billion components
Chapter 2. Architecture and technical overview
C1
L2
L2
C1
39