Introduction.

The first year of production of the Intel Pentium 4 has been somewhat mixed. Initially only available with the Rambus RDRAM compatible i850 chipset, the Pentium 4 has had a somewhat difficult time trying to gain market acceptance. This fact has not been lost on Intel who have been very keen to phase out the P6 based Pentium III processor line in favour of the Pentium 4, but have found this difficult due to the high price of Rambus RDRAM.

As a result of pressure from the marketplace, Intel saw fit to launch a PC-133 SDRAM compatible Pentium 4 chipset in the form of the i845 in late summer 2001. Along with this new chipset Intel also introduced a new packaging format for the Pentium 4 in the form of the Socket 478 connector. The Socket 478 connector is designed to replace the larger Socket 423 connector for future Pentium 4 chips. The release of the i845 chipset which pairs the Pentium 4 to affordable PC-133 SDRAM was always going to generate a large amount of interest from PC companies eager to offer Pentium 4 based systems to the sub £1000 PC market.

Initial press reception of the i845 was somewhat muted, as initial testing indicated that the PC-133 SDRAM compatible chipset offered less performance compared to the Rambus RDRAM compatible i850. In fact Intel sought the i845 and i850 chipsets to be complimentary and not competitive with the i845 being offered to the mainstream PC market whilst the i850 was to move into the high-end PC and x86 compatible workstation market. Whilst Intel currently has two Pentium 4 chipsets on the market, there will be other chipsets from manufacturers such as ALi, SiS, ATi and the highly controversial VIA P4X266.

In typical fashion, any new mainstream chipset from Intel will be adopted by all of the major motherboard manufacturers, hence AOpen launched the AX4BS Pro onto the market. Like much of the PC buying market, we at Processor Emporium were deterred by the high cost of RDRAM and the only limited planned lifespan of the Socket 423 form factor. As a result the first Pentium 4 board which we have received for testing is the Socket 478 compatible, i845 based AX4BS Pro.

The AX4BS Pro is not the first AOpen board which we have tested at Processor Emporium. From our experience, AOpen have made some outstanding boards based upon Intel chipsets such as the i815e based AX3S Pro and the AX3SP Pro. As a result the AX4BS Pro entered testing with high expectations.

The AX4BS Pro also marks another first for Processor Emporium as we have comprehensively updated our test hardware to include 256 MB of system memory as standard (this did appear on other reviews), and the introduction of Nvidia GeForce2 MX based graphics as standard.

To see quite how well the AX4BS Pro did, read on.

Intel i845.

Like all Intel chipsets since the release of the i810 back in 1999, the i845 is based upon the Unified Hub Architecture. The i845 MGCH (Memory and Graphics Controller Hub), contains features such as support for up to 3 GB of main system memory along with standard features such as AGP 4X.

The i845 MGCH is complimented by the now familiar ICH 2 controller which looks after the PCI bus, Ultra ATA 100 Hard Disk Controller and the AC-97 compatible Audio codec.

Specifications.