Multi-book structure

Draft Document for Review April 7, 2004 6:15 pm

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zSeries Application Assist Processors (zAAPs), which are designed to operate asynchronously with the CPs to execute Java programming under control of IBM Java Virtual Machine (JVM) for logical partitions running z/OS. The IBM JVM processing cycles can be executed on the configured zAAPs with no anticipated modifications to the Java applications.

IEEE Floating Point: used by Java and C/C++ applications, the new Binary Floating Point unit halves the number of cycles required on previous servers.

Secondary level Translation Lookaside Buffer (TLB): a secondary cache for Dynamic Address Translation, for both the instruction and data caches, increases the number of buffer entries by a factor of eight.

CP Assist for Cryptographic Function (CPACF): implemented on each PU, the assist function uses five new instructions for symmetrical clear key cryptographic encryption and encryption operations, to accelerate the encryption and decryption of SSL transactions, and VPN encrypted data transfers.

In addition, the following improvements for specific areas are also implemented on z990:

Compression Unit:

The Compression Unit is integrated with the CP Assist for Cryptographic Function, benefiting from combining the use of buffers and interfaces. It is implemented on each PU and provides excellent hardware compression performance.

Checksum offload for IPV4 packets when in QDIO mode for Linux and z/OS:

Checksum Offload provides the capability of calculating the Transmission Control Protocol (TCP), User Datagram Protocol (UDP), and Internet Protocol (IP) header checksums. Checksum verifies the correctness of files. By moving the checksum calculations to a Gigabit or 1000BASE-T Ethernet feature, host CPU cycles are reduced and performance is improved. It is supported by the OSA-Express GbE and 1000BASE-T Ethernet features when operating at 1 Gbps.

The multiple book structure introduced with the z990 servers offers more flexibility, capacity and scalability to the system.

Each book has its own MCM (which contains PUs and L2 cache), memory cards, and MBAs with their STIs. Up to four books are connected through L2 caches by concentric rings, resulting in a single integrated system.

Previous zSeries servers have PU clusters, or PU sets, which are also connected to each other through L2 caches. But in those cases all PUs and L2 caches reside in a single MCM.

The z990 multi-MCM design introduces two types of PU to L2 cache access: a “local” access, when the PU and L2 cache are located in the same MCM (or book), and a “remote” access, when PU and L2 cache are located in different books.

Figure 8-16 shows a two-book z990 server logical view.

Chapter 8. Capacity upgrades 219

990 specifications

The IBM 990 series, often referred to in the context of IBM's pioneering efforts in the realm of mainframe computing, represents a unique chapter in the history of information technology. Introduced in the late 1960s, the IBM 990 series was designed as a powerful tool for enterprise-level data processing and scientific calculations, showcasing the company's commitment to advancing computing capabilities.

One of the main features of the IBM 990 was its architecture, which was built to support a wide range of applications, from business processing to complex scientific computations. The system employed a 32-bit word length, which was advanced for its time, allowing for more flexible and efficient data handling. CPUs in the IBM 990 series supported multiple instructions per cycle, which contributed significantly to the overall efficiency and processing power of the machines.

The technology behind the IBM 990 was also notable for its use of solid-state technology. This provided a shift away from vacuum tube systems that were prevalent in earlier computing systems, enhancing the reliability and longevity of the hardware. The IBM 990 series utilized core memory, which was faster and more reliable than the magnetic drum memory systems that had been standard up to that point.

Another defining characteristic of the IBM 990 was its extensibility. Organizations could configure the machine to suit their specific needs by adding memory, storage, and peripheral devices as required. This modular approach facilitated the growth of systems alongside the technological and operational demands of the business environments they served.

In terms of software, the IBM 990 series was compatible with a variety of operating systems and programming environments, including FORTRAN and COBOL, enabling users to access a broader array of applications. This versatility was a significant advantage, making the IBM 990 an appealing choice for educational institutions, research facilities, and enterprises alike.

Moreover, the IBM 990 was engineered to support multiprocessing, which allowed multiple processes to run simultaneously, further increasing its effectiveness in tackling complex computing tasks.

In summary, the IBM 990 series represents a significant advancement in computing technology during the late 20th century. With a robust architecture, versatile configuration options, and a focus on solid-state technology, the IBM 990 facilitated substantial improvements in data processing capabilities, making it a cornerstone for many businesses and academic institutions of its time. Its impact can still be seen today in the continued evolution of mainframe computing.

IBM manual Multi-book structure, shows a two-book z990 server logical view

Models: 990

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