Early 1999 saw Intel make a number of important introductions to it's processor line up. This introduction that most people will remember is that of the Pentium III. There was also the introduction of the Socket 370 Celeron a short while before the Pentium III, and with this Intel saw the need of a chipset which had many of the high performance features of the i440BX, but not it's price tag. Thus the i440ZX was created to fill this gap.

The ZX chipset is not intended as a high-end chipset solution, but as one that will serve the needs of many desktop users at a lower price to the BX. In essence, the ZX is to the BX what the EX was to the LX.

Intel i440ZX, what does it do?

Firstly, let's discuss the similarities between the ZX and BX chipsets before we discuss their differences. The ZX, like the BX has support for both 66 MHz and 100 MHz Front Side Bus speeds, meaning that all the same processors are supported (Pentium II, Celeron, 100 MHz bus Pentium III). There is also support for AGP 2X, USB and ACPI. The ZX itself is based upon the BX, but it has a number of differences designed to save costs in relation to the BX chipset.

The first main area where the ZX has been reduced in comparison to BX, is it's memory support. The ZX chipset is only capable of handling 4 addressable rows of memory compared to 8 rows on the BX. This means that the ZX chipset can support up to 4 single sided DIMMs or only 2 double sided DIMMS. This is compared to 8 single sided and 4 double sided DIMMs for the BX chipset. This reduces the memory limit of the ZX chipset to only 512 Mb, compared to 1 Gb on the BX.

This reduction in the amount of memory which the ZX can support is seen in the fact that many motherboards using this chipset feature only 2 DIMM sockets compared to 3 or even 4 found on many BX boards.

The other big difference between the ZX and BX chipsets is the number of bus master PCI slots which can be supported. The ZX chipset can provide bus mastering support for only 4 PCI slots compared to 5 slots with the BX. This reduction in bus master supported PCI slots helps to reduce the cost of the ZX chipset.

The ZX chipset is also according to Intel compatible with U/DMA 66 Hard Drives and is optimised for micro-ATX motherboards.

The ZX is currently in production.

ZX in use.