Articles :: Introduction to Chipsets ::

Billy Newsom · 01-01-1997 · Category: Tech-planations

Pentium Pro/II Chipsets

The 440LX chipset has been the mainstay of the Pentium II systems since about September 1997 when it was released. The 440BX should gradually replace it, since it has a 100 MHz memory bus. Its features include:

  • Dual processor support
  • PCI 2.1 support for 4 PCI slots
  • 512 MB of SDRAM or 1 GB of EDO max (512 MB max using unbuffered RAM)
  • ECC, parity, EDO, and SDRAM support on a 66 MHz memory bus
  • Up to four DIMM's, rarely seen in a 3 DIMM, 2 SIMM configuration
  • AGP 1.0
  • USB
  • ACPI
  • Unofficial compatibility with the Pentium Pro using an adapter

The new Intel 440BX chipset (April 1998) has a few improvements over the 440LX. Keep in mind that mixing EDO and SDRAM is not possible on this chipset.

  • Support for 100 MHz memory bus while maintaining the PCI bus at 33 MHz
  • Support for 1 GB of EDO and SDRAM
  • Support for mobile Pentium II
  • Support for SODIMM's
  • Power saving modes in addition to ACPI

The new 440EX chipset (April 1998) has a few downgraded specs compared to the 440LX. Unfortunately, the 440EX "basic" chipset might get confused with the 440BX, a "better" chipset.

  • Support for only 256 MB of EDO or SDRAM
  • No support for ECC or parity RAM
  • Support for only two DIMM's or four SIMM's
  • Support for only one processor

The 440FX is the Natoma PCIset which runs Intel Pentium Pro (Socket 8 or Slot 1) and Intel Pentium II (Slot 1) processors. This chipset supports single and dual processors, ECC, parity, EDO, and FPM RAM up to 1 GB. The motherboards can have up to eight banks of RAM shared among both CPU's.

Drawbacks: no SDRAM, ATA-33, ACPI, or AGP support.

The OPTi Discovery is another Pentium Pro chipset, but I have never seen or heard of a motherboard that uses it. The OPTi website indicates "optional" AGP and UMA support, plus ECC, SDRAM, and parity support. Only 512 MB is allowed, although dual-processor support is available. ATA-33 and USB are standard. Up to six banks of RAM are allowed.

The SiS 5602 is a Pentium II chipset (perhaps also it runs Pentium Pro's, the SiS website is a bit vague) that supports PC97. Note that Intel has yet to release a PC97-compliant chipset for Pentium Pro's or Pentium II's & don't even have a chipset that runs SDRAM for the Pentium Pro/II. SiS is showing their lead here. Their .35-micron chipset is easily better than the 440FX, and it may soon support AGP.

VIA has a Pentium Pro/II chipset called the Apollo P6 680. It allows for up to 1 GB of RAM, including SDRAM, EDO, and ECC/parity support. Up to six banks of RAM are allowed, and quad-processor (dual support for Pentium II) support is available. FIC often carries the VIA chipset products, and this chipset has been used in FIC's Socket 8 motherboard line.


  1. Introduction
  2. What Is a Chipset?
  3. A Brief History of Pentium Chipsets
  4. Triton: It All Started Here
  5. Intel Pentium Chipsets
  6. Non-Intel Pentium Chipsets
  7. Pentium Pro/II Chipsets
  8. The $69.00 Motherboard
  9. High-End Chipsets