PU, SC, and SD chips, SC chip

6947ch02.fm

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

MSC PU PU MSC

PU SD SD PU

PU SC SD PU

PU SD PU CLK

Figure 2-11 MCM chip layout

2.1.8 The PU, SC, and SD chips

All chips use CMOS 9SG technology, except for the clock chip (CMOS 8S). CMOS 9SG is state-of-the-art microprocessor technology based on eight-layer Copper Interconnections and Silicon-On Insulator technologies. The chip’s lithography line width is 0.125 micron.

The eight PU chips come in two versions. The processor units (PUs) on the MCM in each book are implemented with a mix of single-core and dual-core PU chips. Four single-core and four dual-core chips are used, resulting in 12 PUs per MCM.

Eight PUs may be characterized for customer use, one per PU chip. The two standard SAPs and two standard spares are initially allocated to the dual-core processor chips. Each core on the chip runs at a cycle time of 0.83 nanoseconds. Each dual-core PU chip measures

14.1 x 18.9 mm and has 122 million transistors.

Each PU has a 512 KB on-chip Level 1 cache (L1) that is split into a 256 KB L1 cache for instructions and a 256 KB L1 cache for data, providing large bandwidth.

SC chip

The L1 caches communicate with the L2 caches (SD chips) by two bi-directional 16-byte data buses. There is a 2:1 bus/clock ratio between the L2 cache and the PU, controlled by the Storage Controller (SC chip), that also acts as an L2 cache cross-point switch for L2-to-L2 ring traffic, L2-to-MSC traffic, and L2-to-MBA traffic. The L1-to-L2 interface is shared by two P PU cores on a dual core PU chip.

SD chip

The level 2 cache (L2) is implemented on the four System Data (SD) cache chips each with a capacity of 8 MB, providing a cache size of 32 MB. These chips measure 17.5 x 17.5 mm and carry 521 million transistors, making them the world’s densest chips.

36IBM eServer zSeries 990 Technical Guide

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 990 manual PU, SC, and SD chips, SC chip

Models: 990