6947ch03.fm

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

STI links balancing across books and MBAs

Figure 3-4 on page 80 shows a 2084-B16 server’s initial configuration example with two fully populated I/O cages (7 I/O domains on each one).

2084-B16 CEC Cage

Book 0

Book 1

MBAMBAMBAMBAMBAMBA

0

1

2

0

1

2

STIs

 

 

 

 

 

STI Links

 

 

 

 

I/O Cards

 

 

 

 

 

I/O Cage 1

 

 

 

 

I/O Cage 2

I/O Domains

 

 

 

 

 

Figure 3-4 2084-B16 initial configuration example

 

 

 

The 2084-B16 server has two books in the CEC cage. The STI links are distributed across books, MBAs, and I/O cages, as a result of the initial server configuration balancing.

Nearly the same number of STIs of each book’s MBA are used and spread across the two I/O cages, resulting in the best STI link distribution for both performance and availability.

Figure 3-5 on page 81 shows an upgrade from this 2064-B16 server to a model D32, maintaining the same I/O cages and I/O cards.

80IBM eServer zSeries 990 Technical Guide

Page 93 Page 95
Page 94
Image 94
IBM 990 manual STI links balancing across books and MBAs, 2084-B16 CEC Cage, Book, STI Links Cards, Domains
Page 93 Page 95

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.
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