The introduction of the LGA775 processors is only part of the story, and Intel has almost totally revamped the entire platform architecture. In addition to the new processors, Intel has also introduced the 925X, 915P and 915G Express chipsets, with the lineup following the same format as the current i875P / i865PE/G chipsets. We'll be covering these new chipsets in detail in a forthcoming article, but for now, here's a short highlight reel of the chipset features, support and positioning.
The Intel 925X fills the high-end slot, and is the eventual replacement for the i875P enthusiast part, while the 915P is the i865PE equivalent, and the 915G is the i865G counterpart with integrated graphics. These Northbridge chipsets do share a great many features, such as dual-channel memory and PCI Express x16 for graphics, and the differences are more in the area of features than sheer performance. The 925X supports only DDR2 memory (and ECC support) and can only use 800 MHz processors, while the 915P/G can utilize both DDR2 and DDR (either separately or together on one board) as well as handling both 800 and 533 MHz CPUs.
The 925X is the more high-end part, which can serve duty as a workstation or enthusiast desktop, while the 915P/G is the mainstream platform of choice. The 925X also supports a new form of performance acceleration technology, only this time it is hidden within the chipset, likely to dissuade vendors from trying to activate it on 915-level products. Many vendors went this route with the i865PE, and Intel is being crafty with the 925X and only included a few veiled references to it in their documentation.
Intel's Flex Memory Technology is another interesting feature of the new LGA775 chipsets. This allows dual-channel operation and performance, but without the need for matched pairs. Memory capacity becomes the important factor, and if both channels are populated with the same amount of memory, then dual-channel operation is enabled. For example, one bank of 512-MB on channel A can be combined with 2x256-MB on channel B, and the two 512-MB channels are off to the races. Unfortunately, since we haven't got a pile of mismatched DDR2 sitting around, we were unable to test this feature, but it does bring up some intriguing possibilities and would make upgrading memory on these platforms much easier.
The Intel Northbridge selection may have been given a total overhaul, but the ICH6R Southbridge component has received a nice upgrade as well. Intel has finally made the transition to Serial ATA, and the ICH6R includes four SATA ports, while dropping PATA to only one. This effectively means if you want to run multiple ATA devices off the ICH6R, then the hard drives had better be SATA models. The ICH6R also supports standard RAID 0.1, and 0+1, along with Matrix Storage Technology, which allows hard drive hot-swapping, enhanced performance, and the flexibility of multiple volume support to enable both RAID 0 and RAID 1 volumes on a 2-drive array.
The ICH6R Southbridge also offers standard PCI Express support for peripheral cards, integrated LAN, Intel High Definition Audio, USB 2.0, and in the ICH6RW or ICH6W configurations, a nifty Intel Wireless Connect. The High Definition Audio specifications have been upgraded to 192 kHz, 24-bit 8-channel audio support, with enhanced multi-streaming and support for major consumer audio formats like THX and Dolby Digital Surround. The Wireless Connect will be a Southbridge option, and supports 802.11b/g (up to 54 Mbps), WEP and WPA security, and provides an easy-to-use 4-step configuration wizard. With the wireless home becoming a reality, Intel is wise to get on this bandwagon, although Wireless Connect should really be a standard chipset feature.
The other platform change has come in the area of power supplies and PCI Express requirements. The Intel reference motherboards required a 24-pin PSU connector, rather than the standard 20-pin version. These 24-pin models are usually reserved for XEON servers, but there are a few ways around buying a whole new PSU. You can simply use the 20-pin connector, leaving the other 4 pins unused, or purchase a low-cost 20-to-24-pin adaptor cable, each of which worked fine in our testing.
The higher-end PCI Express video cards (like the GeForce 6800 line) proved to be a bit more problematic, and require a whole new 6-pin power cable, which was luckily supplied with the Intel PSU. Hopefully graphics card vendors will package adaptors with their high-end PCI Express cards, thus allowing standard ATX PSUs to be used.