2.1 The POWER5 chip

The POWER5 chip features single-threaded and multi-threaded execution, providing higher performance in the single-threaded mode than its POWER4 predecessor provides at equivalent frequencies. POWER5 maintains both binary and architectural compatibility with existing POWER4 systems to ensure that binaries continue executing properly and that all application optimizations carry forward to newer systems. POWER5 provides additional enhancements such as virtualization, improved reliability, availability, and serviceability at both chip and system levels, and it has been designed to support speeds up to 3 GHz.

Figure 2-2shows the high-level structures of POWER4 and POWER5 processor-based systems. The POWER4 scales up to a 32-way symmetric multiprocessor. Going beyond 32 processors increases interprocessor communication, resulting in higher traffic on the interconnection fabric bus. This can cause greater contention and negatively affect system scalability.

 

 

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Figure 2-2 POWER4 and POWER5 system structures

 

 

 

 

 

Moving the L3 cache provides significantly more cache on the processor side than was available previously, thus reducing traffic on the fabric bus and enabling POWER5 processor-based systems to scale to higher levels of symmetric multiprocessing. The POWER5 supports a 1.9 MB on-chip L2 cache, implemented as three identical slices with separate controllers for each. Either processor core can independently access each L2 controller. The L3 cache, with a capacity of 36 MB, operates as a backdoor with separate buses for reads and writes that operate at half processor speed.

Because of the higher transistor density of the POWER5 0.13-µm technology, it was possible to move the memory controller on-chip and eliminate a chip that was previously needed for the memory controller function. These changes in the POWER5 processor also have the significant side benefits of reducing latency to the L3 cache and main memory, as well as reducing the number of chips that are necessary to build a system.

The POWER5 processor supports the 64-bit PowerPC® architecture. A single die contains two identical processor cores, each supporting two logical threads. This architecture makes the chip appear as a four-way symmetric multiprocessor to the operating system. The POWER5 processor core has been designed to support both enhanced simultaneous multi-threading (SMT) and single-threaded (ST) operation modes.

20p5-570 Technical Overview and Introduction

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IBM P5 570 manual POWER5 chip, POWER4 POWER5

P5 570 specifications

The IBM P5 570 is a high-performance server that was designed for enterprise-scale computing, offering a blend of advanced technologies and a flexible architecture. Launched as part of IBM's Power5 server line, the P5 570 stands out for its robust processing capabilities and extensive scalability, making it a preferred choice for businesses requiring reliable and efficient computing solutions.

At the heart of the P5 570 is the IBM Power5 processor, which employs simultaneous multi-threading (SMT) technology. This allows the processor to handle two threads per core, effectively doubling the throughput for workloads ideally suited to multi-threading. The server typically features a configuration of up to 32 Power5 processors, providing an impressive compute power that supports demanding applications, ranging from databases to complex enterprise resource planning (ERP) systems.

The P5 570 architecture supports a wide range of memory configurations, with a maximum memory capacity of up to 512 GB. Utilizing IBM’s proprietary Chip Memory technology, it can deliver high bandwidth and low latency, significantly enhancing performance for memory-intensive applications. Furthermore, the integrated memory controller architecture optimizes memory access, ensuring that critical workloads run smoothly.

Scalability is a key characteristic of the P5 570, with the ability to expand processing power and memory capacity as an organization’s needs grow. The server supports various operating systems, including AIX, Linux, and IBM i, which provides flexibility for diverse IT environments. This versatility ensures that companies can run their preferred applications without the need for substantial system overhauls.

In terms of storage, the P5 570 utilizes advanced RAID technology and supports a variety of disk configurations, ensuring that data integrity and availability are maintained. Coupled with built-in security features, such as the IBM Trusted Foundation, which establishes a secure boot environment, the P5 570 offers a reliable platform for mission-critical workloads.

Finally, the IBM P5 570 is designed for high availability and redundancy. Features like hot-swappable components and advanced error detection and recovery mechanisms minimize downtime, making it a dependable choice for businesses that operate around the clock. Combined with its powerful hardware and versatile software support, the IBM P5 570 remains a formidable player in the high-performance server arena.