Intel Workstation Chipsets for Pentium 4 and Xeon

Intel has developed several chipsets for workstations based on the Pentium 4 and Xeon processors. The following sections describe these chipsets in detail; Table 4.53 provides a quick reference to their features.

Table 4.53. Workstation Chipsets

Chipset	860	E7205	E7505	E7525
Code name	Colusa	Granite Bay	Placer	Tumwater
Date introduced	May 2001	Dec. 2002	Dec. 2002	2004
Part number	82860	E7205	E7505	E7525
Bus speeds	400MHz	533/400MHz	533/400MHz	800MHz
Supported processors	Xeon	Pentium 4[5]	Xeon 533MHz FSB and 512KB L2 cache[5]	Xeon 800MHz FSB
SMP (dual CPUs)	Yes (2)	No	Yes (2)	Yes (2)
Memory type	4 RDRAM PC800[1]	DDR200/266 SDRAM (unbuffered)	DDR200/266 dual-channel	DDR333 or DDR2-400 (dual-channel)
Parity/ECC	Both	Both	Both	Both
Maximum memory	4GB (with two MRHR chips)	4GB	16GB	16GB
Memory banks	Up to 4[3]	Up to 4	Up to 6 (registered memory) or 4 (unbuffered memory)	Up to 8
PCI support	2.2	2.2	2.2	2.2
PCI speed/width	32-bit/33MHz[2]	32-bit/33MHz	32-bit/33MHz[4]	32-bit/33MHz[6]
AGP slot	AGP 4x/2x	AGP8x-1x	AGP8x-1x	PCI-Express x16
Integrated video	None	None	None	None
South Bridge (Hub)	ICH2	ICH4	ICH4	ICH5R or 6300ESB[7]

^[5] Supports HT Technology.

^[1] Up to eight on motherboards with MRHR chips.

^[3] Two banks when MRHR chip is not present.

^[2] 64-bit 33/66MHz on motherboards with P64H chips.

^[4] 64-bit 33/66MHz and PCI-X on motherboards with P64H2 chips.

^[6] 64-bit 33/66MHz and PCI-X on motherboards with 6700PXH PCI hub chips.

^[7] 6300ESB incorporates dual SATA RAID 0,1 host adapters; four USB 2.0 ports; and one PCI-X 64-bit/66MHz (64/66) bus with support for up to 4 PCI-X 64/66 interfaces.

Intel 860

The Intel 860 is a high-performance chipset designed for the Socket 602 (Pentium 4based) Xeon processors for DP workstations. The 860 uses the same ICH2 as the Intel 850 but uses a different MCHthe 82860, which supports one or two Socket 602 ("Foster") Xeon processors. The other major features of the 82860 are similar to those of the 82850, including support for dual 400MHz RDRAM memory channels with a 3.2GBps bandwidth and a 400MHz system bus. The 82860 MCH also supports 1.5V AGP 4x video cards at a bandwidth exceeding 1GBps.

The 860 chipset uses a modular design, in which its two core chips can be supplemented by the 82860AA (P64H) 66MHz PCI Controller Hub and the 82803AA MRHR. The 82860AA supports 64-bit PCI slots at either 33MHz or 66MHz, and the 82803AA converts each RDRAM memory channel into two, which doubles memory capacity. Thus, whether a particular 860-based motherboard offers 64-bit or 66MHz PCI slots or dual-channel RDRAM memory depends on whether these supplemental chips are used in its design.

Intel E7205

The Intel E7205 chipset, known as Granite Bay during its development, is designed to support both workstation and high-performance PC applications. It supports DDR200/266 SDRAM modules with a system bus speed up to 533MHz and uses the ICH4 I/O controller hub, just as some versions of the 845 chipset do. However, the E7205 supports ECC and parity-checked memory for better system reliability and supports all standard-voltage speeds of AGP from 1x to 8x with an AGP Pro slot (nonstandard 3.5V versions of AGP once sold by some vendors such as 3dfx will not work). It supports hyper-threading for use with the 3.06GHz and faster Pentium 4 processors.

Intel E7505

The Intel E7505 chipset, known as Placer during its development, is in some ways an updated version of the 860 chipset, adding support for faster processors and more advanced hardware than the 860 offers.

The E7505 supports a system bus of up to 533MHz, matching the single or dual Xeon 533MHz FSB and 512KB L2 cache processors it supports; it also supports the HT Technology included in these processors. The E7505 supports pairs of DDR200/266 memory up to 16GB total, four times as much as the E7205 and the 860. It can use up to six registered or four unbuffered memory modules and supports ECC. Its Intel x4 single-device data correction (SDDC) can correct up to four errors per memory module for better system reliability.

Its AGP Pro slot supports all speeds of AGP from 1x to 8x (except for the nonstandard 3.5V versions of AGP once sold by some vendors), and it uses the ICH4 I/O controller hub. To achieve 66MHz/64-bit PCI and 133MHz PCI-X support, the E7505 can be used with up to three optional P64H2 (82870P2) chips, an improved version of the P64H chip that is an optional part of the 860 chipset.

Intel E7525

The Intel E7525 chipset, known as Tumwater during its development, combines features derived from the Intel 9xx series of desktop chipsets with support for the latest 800MHz versions of the Intel Xeon processor and the 64-bit Xeon processor with 2MB L2 cache. The E7525 supports up to 16GB of dual-channel DDR-2 400 (four DIMMs per channel) or DDR333 (three DIMMs per channel) and protects the contents of memory with support for ECC, Intel x4 single-device data correction (SDDC), DIMM sparing, DIMM scrubbing, and memory mirroring. DIMM sparing (also known as memory mirroring) sets aside a spare bank of memory that is used automatically if one of the primary banks develops too many single-bit errors. DIMM scrubbing (also known as memory scrubbing) tests memory during idle periods. Memory mirroring uses one bank to hold a copy of the other.

The E7525 chipset is Intel's first workstation chipset with support for PCI-Express x16 graphics. It supports either the ICH5R or ESB6300 I/O Controller Hub chip. To achieve 66MHz/64-bit PCI and 133MHz PCI-X support, the E7525 can be used with up to two optional 6700 PXH 64-bit PCI hub chips.