Intel has been having a fair bit of trouble holding back the torrent of new AMD processor introductions, especially the last dual-release of the Athlon 64 FX-55 and 4000+. Intel had a competitive selection of high-end Socket 478 processors not that long ago, but the transition to LGA775 and DDR2 failed to upgrade overall performance, and really allowed AMD to get the upper hand. Add to this the announcement that the current Pentium 4 Prescott core will not be released at 4 GHz or higher speeds, and you've got a real dilemma in terms of what Intel can do to increase performance. One avenue is the old front-side bus speed increase, which Intel used to great effect with their 533 and 800 MHz FSB upgrades, and is now looking to ratchet over 1 GHz using their fastest desktop model yet, the Pentium 4 Extreme Edition.
At first glance, the release of the Pentium 4-3.46 GHz Extreme Edition may seem a bit unusual. After all, the 3.46 GHz core speed is not much higher than the current Pentium 4-3.4 GHz EE, and certainly not enough to warrant much hoopla. But this is a bit more than just a processor introduction, as the Pentium 4-3.46 GHz EE may only run slightly higher than 3.4 GHz, but the processor front-side bus is the area where the speeds really jump. Instead of the current 800 MHz FSB, the new Pentium 4-3.46 GHz EE has been upgraded to a 1066 MHz (1.06 GHz) bus, and is similar to the prior 533 and 800 MHz bus speed transitions.
In terms of physical design, the latest Pentium 4 Extreme Edition is basically the same as its predecessors. The core is built on a 0.13-micron process, the processor features and same 512K L2 and 2-MB of L3 cache as the current models, and since the core speed is virtually the same, thermals and core voltages only increase nominally. Although the base specifications remain unchanged and the Pentium 4-3.46 GHz EE still uses the 775-pin LGA package, it does run on the 1066 MHz FSB, so the platform base has been upgraded to the 925XE chipset.
The Intel 925XE is basically the Intel 925X with support for the 1066 MHz bus speed. Otherwise, the features and hardware are equivalent, and the i925XE uses dual-channel DDR2, and through the ICHR6 Southbridge, includes PCI Express x16 graphics and PCI Express x1 peripheral support, along with Intel Matrix RAID and High Definition Audio. The ICHR6 also supports up to 4 Serial ATA drives, along with legacy support for a Parallel ATA channel and up to six PCI slots. The processor bus has naturally increased to 1066 MHz to accommodate the Pentium 4-3.46 GHz EE, but legacy support also extends to the processors as well, with the Intel 925XE handling both 533 MHz and 800 MHz LGA775 CPUs.
The key upgrade to the Intel 925XE chipset is the 1066 MHz speed jump to the processor bus, and exactly how this relates to other system bus speeds. DDR2 is the most important, and even running at standard, dual-channel DDR-533 speeds, this provided far more bandwidth than the 800 MHz Pentium 4 processors required. Extra bandwidth is never a bad thing, and now that Intel has upgraded to the 1066 MHz FSB, the 8.5 GB/sec. of memory bandwidth are now matched by the 8.5 GB/sec. of CPU bandwidth. This is similar to the synchronous link between the 800 MHz Pentium 4 and dual-channel DDR400, and look for memory performance and bandwidth to increase significantly with the Pentium 4-3.46 GHz EE running on the Intel 925XE.
The i925XE reference motherboard for this review is the Intel D925XECV2, and it is quite similar to the current i925X motherboards in terms of both design and hardware support. It is a standard ATX board, and features support for Pentium 4 processors on the 533, 800 and 1066 MHz bus. The motherboard includes four DDR2 sockets, and is capable of both DDR2-533 and DDR2-400 module support. The design includes one PCI Express x16 graphics and two PCI Express x1 peripheral slots, as well as four legacy PCI slots. There are also four Serial ATA ports, a single Parallel ATA port, and one floppy connector, and Intel offers both Gigabit LAN and their High Definition Audio subsystem.
In terms of usability and performance, the latest Intel high-end board shows a continued improvement from their design team. Intel has been long known as a manufacturer of enthusiast-level processors and sedate, mainstream motherboards, but this is starting to change. Intel recently started allowing a modicum of overclocking features through a "burn-in mode", and the D925XECV2 includes this, and a relatively ample selection of memory timings, DDR2 voltage selection, hardware monitoring, and SATA RAID features. The Intel D925XECV2 won't have you tossing away your ASUS Deluxe board, but it does show the chip giant moving in the right direction.