System buses, Memory throughput

11S1234567YL12345678901 FRU P/N EC Level

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	Seven digits	Twelve digits
	Seven digits	IBM plant identificator
	IBM part number	IBM plant identificator
		and part serial number

Figure 2-8 IBM memory certification label

Sometimes OEM vendors attach a label to their DIMMs that reports the IBM memory part number but not the barcode or the alphanumeric string.

In case of system failure caused by OEM memory installed in the system, the first thing to do is to replace the suspected memory with IBM memory, then check whether the problem is corrected. Contact your IBM representative for further assistance if needed.

2.3.3 Memory throughput

The memory subsystem throughput is based on the speed of the memory, not the speed of the processor. An elastic interface, contained in the POWER5 chip, buffers reads and writes to and from memory and the processor. On DDR1 cards, there are two SMIs, each with a single 8 byte read and 2 byte write DDR bus to the processor on each processor card. A DDR bus allows double reads or writes per clock cycle. If 266 MHz memory is installed, the throughput is (16 x 2 x 266.5) + (4 x 2 x 266.5) or 10660 MB/second or 10.41 GB/second per processor card. For a building block with two processor cards, this value is doubled, or 20.82 GB/second.

DDR2 processor cards contain an additional set of two SMIs to manage the increased throughput. However in this configuration the paths are 4 bytes for read operations and 2 bytes for write. Therefore the throughput is (4 + 2) * 4 * 1066 = 24.98 GB/s or 49.96 GB/s for a 4-way node. These values are maximum theoretical throughputs for comparison purposes only.

The POWER5 processor’s integrated memory controller further reduces latency over the previous outboard controller on POWER4 systems to the SMI chips by requiring fewer cycles in order to set up memory addressing in the hardware.

2.4 System buses

The following sections provide additional information related to the internal buses.

2.4.1 RIO-2 buses and GX+ card

Each DCM provides a GX+ bus that is used to connect to an I/O subsystem or Fabric Interface card. In a p5-570 drawer, there are two GX+ buses, one from each processor card. Each p5-570 has one GX slot with a single GX+ bus. The GX+ slot is not active unless the second processor card is installed. It is not required for CUoD processor cards to be activated in order for the associated GX+ bus to be active. The p5-570 provides two external RIO-2 ports, which can operate up to 1 GHz. An add-in GX+ adapter card (Remote I/O expansion card, FC 1800) adds two more RIO-2 ports. When this card is installed, PCI adapter slot 6

Chapter 2. Architecture and technical overview 27

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.