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 describe these chipsets in detail.
Intel 860
The Intel 860 is a high-performance chipset designed for the Socket 602 (Pentium 4–based) Xeon processors for DP workstations. The 860 uses the same ICH2 as the Intel 850 but uses a different MCH—the 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 100MHz 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.