The 440 chipset line were some of the first projects I worked on. My memory of that time is extremely faded though. If I recall, ZX was a lower cost version of BX. So it might not be too surprising that some utilities report them as the same. Likely just a few supported features different to save some money. The BX chipset was a workhorse, and likely one of the best chipset products Intel ever built. If I dig far enough, I might actually have some documents and emails dating back that far
Doing a quick search ended up with this...
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www.pctechguide.com/chip ··· zx-440gx440BX
The PC’s system bus had been a bottleneck for too long. Manufacturers of alternative motherboard chipsets had made the first move, pushing Socket 7 chipsets beyond Intel’s 66MHz. Intel’s response came in April 1998, with the release of its 440BX chipset, which represented a major step in the Pentium II architecture. The principal advantage of the 440BX chipset is support for a 100MHz system bus and 100MHz SDRAM. The former 66MHz bus speed is supported, allowing the BX chipset to be used with older (233MHz-333MHz) Pentium IIs.
The 440BX chipset features Intel’s Quad Port Acceleration (QPA) to improve bandwidth between the Pentium II processor, the Accelerated Graphics Port, 100-MHz SDRAM and the PCI bus. QPA combines enhanced bus arbitration, deeper buffers, open-page memory architecture and ECC memory control to improve system performance. Other features include support for dual processors, 2x AGP, and the Advanced Configuration Interface (ACPI).
440ZX
The 440ZX is designed for lower cost form factors without sacrificing the performance expected from an AGPset, enabling 100MHz performance in form factors like microATX. With footprint compatibility with the 440BX, the 440ZX is intended to allow OEMs to leverage BX design and validation investment to produce new systems to meet entry level market segment needs.
