Intel Sonomo improves wireless integration in mobile devices

Together with the explosive worldwide growth in WLAN hotspots, the unveiling of Intel’s second-generation mobile technology platform in January 2005 is expected to lead to the completion of the notebook PC’s transition from a portable to a wireless device, fuelled by the introduction of the Centrino brand two years earlier. Predictions are that the number of frequent WLAN hotspot users will have increased from less than 1 million in 2002 to over 30 million by 2006.

Sonoma improves on each of Centrino’s key mobile technologies, comprising:

  • the i915 Graphics and Memory Controller Hub (GMCH)
  • the IO Controller Hub (ICH) 6-M, and
  • the Intel PRO/Wireless 2915 a/b/g Network Interface Controller (NIC)
  • a number of new Pentium M processors.

The centrepiece of the Sonoma package is the 915 Express chipset, formerly codenamed Alviso, which provides the support for several new technologies expected to provide a foundation for notebook PCs for the next decade:

  • mobile PCI Express (PCIe) and ExpressCard technology
  • Serial Advanced Technology Attachment (SATA) interface
  • PCIe External Graphics (PEG) interface
  • Double Data Rate (DDR) memory, and
  • Intel High Definition (HD) Audio.

The new platform delivers both on CPU and graphics performance through scaling in core and bus frequencies as well as with microarchitecture enhancements including doubling processor cache size. The graphics performance improves by 2x over the previous generation platform. GMCH enables an enriched media experience through incorporation of Intel HD Audio and higher-speed interfaces.

The PCIe Mini Card replaces the Mini PCI card, typically used on the mobile motherboard for build-to-order optional functions. The ExpressCard module is a new add-in card that replaces the CardBus PC Card. Both of these new cards provide not only PCIe bus connectivity but also USB 2.0 connectivity through the same connector.

SATA is the evolution of the Parallel ATA bus for connecting mass storage (hard and optical drives) on mobile platforms initially upgrading the transfer rate from 133 MBps to 150 MBps with ability to scale to 300 MBps and 600 MBps in future. SATA is also friendly to mobile form factors since it needs a much smaller connector than parallel ATA.

To support PCIe, SATA, and Intel HD Audio, a newer cross-chip interconnect, Direct Media Interface (DMI), between the GMCH and the ICH, was developed. This upgraded the cross-chip transfer rate from 266 MBps to 2 GBps The DMI enables concurrent traffic and isochronous data transfer capabilities.

The new chipset supports next-generation memory technology by implementing the DDR2 specification, an evolutionary technology that extends first-generation DDR. The DDR2 specification allows increased clock rates over DDR while operating at 1.8V vs. 2.5V on earlier-generation technology.

Finally, the new platform’s support for Intel HD Audio means significant improvements over AC’97 previous-generation integrated audio and sound cards. While the latter supports only six channels at 48 kHz/20-bit, Intel HD Audio hardware is capable of delivering the support and sound quality for up to eight channels at 192 kHz/32-bit quality and enables Dolby 5.1/7.1 surround sound audio out capability, which can be used with an SPDIF optical interface for component audio amplifiers.

In addition to the improvements afforded by the new chipset, there have also been changes to the wireless technology. As well as providing support for the 802.11a, 802.11b and 802.11g wireless networking standards, Sonoma’s Intel PRO/Wireless 2915ABG NIC includes a coexistence solution that mitigates interference with wireless Bluetooth human interface devices (HIDs). Wireless connectivity is also enhanced with industry-standard WLAN security support and a simplified user interface.

Seven new Pentium M processors are available as part of the package. Formerly codenamed Dothan, these 700 series chips retain the same basic design as the original Pentium M, but are manufactured on a 90nm process. At 84mm2 the die size remains in the same neighbourhood as the original Pentium M, even though the 700 series contains around 140 million transistors, most of which make up the 2MB L2 cache. The five CPUs that use the faster 533MHz FSB are identified by processor numbers that are divisible by ten. The top-of-range Pentium M 770 runs at 2.13 GHz. At the other end of the range, the Pentium 753 ULV (Ultra Low Voltage) version uses the 400MHz FSB and runs at 1.2 GHz.