What is Intel’s 925X PCI Express Chipset

In the summer of 2004 Intel introduced a new family of chipsets that they claimed brought the most profound changes in PC platform architecture in more than a decade. The relative positioning of the chipsets – codenamed Alderwood and Grantsdale – is similar to that of the Canterwood and Springdale chipsets which preceded it. The 925X PCI Express chipset is the higher-end of the two, boasting a number of specific performance enhancements and being designed to deliver the ultimate gaming experience when coupled with Pentium 4 Extreme Edition CPUs.

The new chipsets are designed for use with the latest Prescott-cored Pentium 4 CPUs, designated by the new numeric model naming scheme – initially the 560 at 3.6GHz, down to the 520 at 2.8GHz. They will therefore only be used in motherboards that support Intel’s innovative LGA775 package, which facilitates a direct electrical connection between the chip module substrate and the motherboard which the company claims will provide the robust power and signal delivery needed for future performance headroom.

All the new chipsets support Hyper-Threading, an 800MHz FSB and dual-channel DDR2-533 memory and enable a broad spectrum of new platform capabilities:

  • Intel High Definition Audio enables multistreaming, 7.1 surround sound and dynamic jack retasking in a groundbreaking PC audio solution that provides performance comparable to high-end consumer electronics (CE) equipment.
  • Intel Matrix Storage Technology provides the performance benefits of RAID 0 for media-intensive applications and the added protection of RAID 1 for critical digital media files and data on just two drives.
  • The I/O Controller Hub 6 (ICH6R version) supports four 1.5 GBps Serial ATA (SATA) ports with Advanced Host Controller Interface (AHCI) capability, enabling Native Command Queuing for enhanced storage performance.
  • Four PCI Express x1 high-speed expansion ports are ready for Gigabit Ethernet and future applications, including multiple TV tuners implemented in a single card.
  • Intel Wireless Connect Technology enables users to create or expand a wireless network without external access point hardware. Intel Wireless Connect Technology requires a specific Intel 9XX Express Chipset and a separate Intel wireless LAN solution to operate.

Intel’s new Flex memory system introduces some welcome flexibility, with dual-channel operation no longer being restricted to identical memory modules bought in matched pairs. Now the requirement is simply for the same amount of memory – whatever the configuration – in each of the two available banks.

Foremost amongst the innovations is the introduction of the PCI Express (PCX) bus technology. As digital video content becomes ever more important in today’s electronic universe, no single aspect of the personal computing platform requires as much performance increase as the graphics interface.

The new chipsets address this need in the shape of the revolutionary 16x PCI Express graphics interface, as its name implies, an aggregation of 16 lanes. This provides the increased bandwidth and scalability necessary to tackle the most demanding multimedia tasks, with up to four times the theoretical maximum bandwidth over previous generation AGP8X-based solutions – up to 4 GBps of peak bandwidth per direction and up to 8 GBps concurrent bandwidth.

AGP is unceremoniously consigned to history, the new chipsets providing no AGP interface at all. In time 1x PCX will replace the decade-old PCI standard.