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This chapter is from the book

This chapter is from the book

Broadcom ServerWorks Chipsets for Intel Processors

Starting in 1997, ServerWorks (a Broadcom company originally known as Reliance Computer Corporation) introduced its first server chipsets for Intel processors. Today, ServerWorks is second only to Intel as the major supplier of server chipsets for Intel-based servers.

Early ServerWorks chipsets included the ServerSet I (also known as the Champion 1.0 chipset) and the ServerSet II. ServerSet I supported up to six Pentium Pro processors and featured two 32-bit PCI buses. ServerSet II supported up to four Pentium II Xeon processors and featured a 64-bit PCI bus. These chipsets were discontinued several years ago.

Current ServerWorks chipsets support the Pentium III Xeon and Xeon DP and MP (based on Pentium 4) processors. Although ServerWorks uses the North Bridge and South Bridge terminology for its chipsets, its current chipsets also include memory controller and I/O bridge chips. Thus, ServerWorks chipsets more closely resemble E7xxx-series Intel chipsets than Intel's 8xx or 9xx chipsets.

Several major motherboard and system builders, including Intel, have used Champion- and Grand Champion–series chipsets for multiprocessor server motherboards and systems.

ServerWorks Chipsets for Intel Pentium III Xeon Processors

ServerWorks currently makes three chipsets for the Pentium III Xeon processors:

  • Champion HE (also known as Champion Enterprise)— Supports up to four processors with 100MHz FSB; the North Bridge is the NB6536 2.0HE.
  • Champion HE-SL (also known as Champion Volume)— Supports up to two processors with 133/100MHz FSB; the North Bridge is the NB6576.
  • Champion LE (also known as Champion Entry)— Supports up to two processors with 133/100MHz FSB; the North Bridge is the NB6635 3.0LE.

Originally, this series of chipsets was known as the ServerSet III series.

All three North Bridge chips can be paired with either the OSB4 or CSB5 South Bridge chip to form a chipset. The OSB4 features UDMA/33 ATA/IDE hard disk host adapter, USB 1.1 ports, and an LPC connection to a Super I/O chip. The CSB5 features an UDMA/100 ATA/IDE hard disk host adapter, USB 1.1 ports, and an LPC connection to a Super I/O chip. Most motherboards that use a Champion-series chipset use SCSI-based hard disks or RAID arrays instead of ATA hard disks, so there is little practical difference between these South Bridge chips.

Table 3.14 provides an overview of the Champion series of chipsets for the Pentium III Xeon processor.

Table 3.14. Champion Chipsets for Pentium III Xeon

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The Champion LE Chipset

The Champion LE chipset is the simplest of the current Champion series, using only North Bridge and South Bridge chips. For greater reliability than with desktop-adapted chipsets, Champion LE, like all current ServerWorks server chipsets, uses registered memory.

Champion LE supports two 64-bit/66MHz PCI expansion slots via the South Bridge chip. However, if you need additional 64-bit slots, Champion LE is not a suitable choice. Thus, Champion LE is best suited to basic dual-processor server applications.

The Champion HE-SL Chipset

Although the Champion HE-SL chipset supports two processors, as does the Champion LE, it is a more powerful and flexible chipset. It supports AGP 2x graphics, and ECC registered memory must be installed in matched pairs to support memory interleaving for better memory performance.

However, the most significant improvement in Champion HE-SL over its Champion LE sibling is its support for both 3.3V (66MHz) and 5V (33MHz) 64-bit PCI slots. This comes via the third component in the HE-SL chipset, the CIOB20 I/O bridge. The CIOB20 (also known as the NB6555 IO Bridge 2.0 chip), provides a 64-bit PCI bridge between the North Bridge and 64-bit PCI slots. The connection to the North Bridge uses ServerWorks's own Inter Module Bus (IMB) high-speed connection. IMB runs at 1GBps, which is four times faster than Intel's Hub Architecture 1.0 or 1.5 or the VIA V-Link 4x interconnections.

If you need to use several PCI cards (33MHz or 66MHz) in a server, the Champion HE-SL is a better choice than the Champion LE.

The Champion HE Chipset

The Champion HE is the most powerful of the Champion series. It supports four Pentium III Xeon processors and uses a fourth ServerWorks chipset component, the MADP memory controller chip. In a four-way configuration, four MADP chips are used, but in a two-way configuration, only one MADP chip is used (see Figure 3.24).

03fig19.gif

Figure 3.24 The ServerWorks Champion HE chipset in a typical four-way configuration.

The MADP chip supports memory interleaving for better memory performance in both two-way and four-way configurations.

ServerWorks Chipsets for Intel Xeon Processors

ServerWorks currently makes three chipsets for the Xeon processors based on the Pentium 4:

  • Grand Champion HE (also known as Grand Champion Enterprise)— Supports up to four processors with 400MHz FSB; the North Bridge chip is called CMIC-HE.
  • Grand Champion LE (also known as Grand Champion Volume)— Supports up to two processors with 533/400MHz FSB; the North Bridge chip is called CMIC-SL.
  • Grand Champion SL (also known as Grand Champion Entry)— Supports up to two processors with 533/400MHz FSB; the North Bridge chip is called CMIC-LE.

Originally, this series of chipsets was to be known as the ServerSet IV series.

All three North Bridge chips can be paired with either the CSB5 or CSB6 South Bridge chip to form a chipset. The CSB6 is the most advanced South Bridge chip used by any ServerWorks chipset to date. It includes three ATA-100 ATA/IDE host adapters; support for ATA RAID 0, 1, and 5; 64-bit PCI bus; 400MBps connection to the North Bridge; and USB 1.1 ports.

Table 3.15 provides an overview of the Grand Champion series of chipsets for Xeon processors.

Table 3.15. Grand Champion Chipsets for Intel Xeon

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The GC-SL (Grand Champion Entry) Chipset

The Grand Champion SL chipset is the simplest of the current Grand Champion series. Its North Bridge chip incorporates a single IMB I/O interface and a single Thin-IMB interface to the South Bridge. It supports up to 4GB of RAM. RAM contents are protected with 128-bit ECC and spare memory technologies. The optional CIOB-E bridge provides Gigabit Ethernet support, while the optional CIOB-X2 I/O bridge provides PCI-X support up to 133MHz. In its basic North Bridge/South Bridge configuration, Grand Champion SL is suitable for basic server designs. However, when the CIOB-X2 PCI-X bridge is added, it is also suitable for midrange server designs.

The GC-LE (Grand Champion LE) Chipset

The dual-processor Grand Champion LE is designed to handle four times the memory (16GB) of the Grand Champion SL. It also supports two CIOB-X2 PCI-X I/O bridge chips, enabling a motherboard to have up to six PCI-X 100/66MHz cards, up to three PCI-X 133MHz cards or a mix of PCI-X cards and onboard devices. Thus, if you need support for several PCI-X cards, or a mix of PCI-X cards, a high-speed integrated SCSI host adapter and a Gigabit Ethernet adapter as in Figure 3.25, the Grand Champion GC-LE chipset is a better choice than the GC-SL.

03fig35.gif

Figure 3.25 A typical implementation of the Grand Champion LE server chipset.

Figure 3.25 illustrates the block diagram of a typical server using the GC-LE chipset.

The GC-HE (Grand Champion HE) Chipset

The Grand Champion HE is the most powerful of the Grand Champion series. It supports four Xeon MP processors and incorporates three IMB I/O interfaces for the fastest memory interfacing of any GC-series ServerWorks chipset. With support for up to 64GB of memory, its memory contents are protected with 128-bit ECC, chipkill, spare memory, memory mirroring, and hot-plug memory card support technologies. The GC-HE uses five REMC memory controller chips in a four-way configuration: four in the data path and a fifth one in the address path.

Figure 3.26 illustrates a four-way implementation of the GC-HE chipset.

03fig36.gif

Figure 3.26 A typical implementation of the Grand Champion HE server chipset.

ServerWorks South Bridge and Support Chips

All ServerWorks Champion and Grand Champion chipsets contain South Bridge chips, and many of them also contain I/O bridge and memory controller chips. The South Bridge chips used by ServerWorks chipsets support ATA/IDE, PCI, and legacy I/O devices. Table 3.16 provides more information about the South Bridge chips used with Champion and Grand Champion chipsets.

Table 3.16. Champion/Grand Champion South Bridge Chips

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The I/O bridge chips provide support for PCI-X slots and, in some versions, Gigabit Ethernet. Table 3.17 provides more information about the I/O bridges used by the Champion and Grand Champion chipsets.

Table 3.17. Champion/Grand Champion I/O Bridge Chips

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The high-end HE and GC-HE chipsets also use memory controller chips to provide support for memory interleaving. Memory interleaving divides memory into banks, permitting memory to be accessed more quickly for improved performance. Table 3.18 provides more information about these chips.

Table 3.18. Champion/Grand Champion Memory Controller Chips

View Table
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