Intel D5400XS Skulltrail Hands-On

One glance at the Intel D5400XS motherboard with its dual-CPU sockets and active chipset cooling is enough to tell you that this isn't your normal PC motherboard. Code named Skulltrail, the Intel D5400XS represents Intel's ultimate PC motherboard platform. Regular motherboards only have a single CPU socket, two PCI Express slots, and support for only one of the two competing dual-GPU formats. In comparison, the Skulltrail has two processor sockets, four x16 PCI Express video card slots, and built-in support for both SLI and CrossFire. If you set two Intel Core 2 Extreme QX9775 processors in the board, you have an 8-core monster ready to run.

The Skulltrail code name follows the pirate-naming theme started with the "Bonetrail" code name for Intel's X38 motherboard. Intel was able to supercharge the board by making a couple of aggressive design decisions. Engineers built the board around the Intel 5400 workstation chipset instead of using its standard X38 or P35 desktop chipset. The chipset choice gives Skulltrail advanced features not available on normal desktop motherboards, such as dual-CPU support, but it also brings new requirements, including a new CPU socket, LGA771, and DDR2 FBDIMM memory. We aren't thrilled with the FBDIMM requirement, but the modules aren't too difficult to find and don't cost much more than unbuffered DIMMS.

The board will work with the new Intel Core 2 Extreme QX9775 processor, as well as LGA771 Xeon processors. It won't be able to handle the more common LGA775 processors, such as the Core 2 Quads or Core 2 Duos, but the motherboard's limited CPU compatibility illustrates Skulltrail's elite status in Intel's product lineup. The motherboard's primary CPU option, the quad-core 3.2GHz QX9775 is more powerful than any LGA775 chip currently available. Intel hasn't announced any future Skulltrail-compatible processors besides the QX9775 and does not guarantee future compatibility with its upcoming "Nehalem" processors.

On the graphics side, the Intel D5400XS features four PCI Express x16 card slots and can handle both SLI and CrossFire. Support for the competing dual-video card standards from Nvidia and AMD are usually mutually exclusive on PC motherboards. If the motherboard supports CrossFire, it won't support SLI and vice versa. Intel boards commonly support CrossFire, but designers were able to drop a pair of Nvidia nForce 100 chips into the board to add two-way SLI support.

The Intel Core 2 Extreme QX9775 doesn't have much competition at the top. We benchmarked two QX9775 processors against a single chip to see the performance difference between eight and four cores. The LGS771 socket limitation prevented us from dropping a dual-core into the Skulltrail, so we had to run our Intel Core 2 Extreme X6800 in an LGA775 motherboard for our dual-core performance comparison. We selected a handful of multithreaded games and synthetic benchmarks including 3DMark06, Valve Particle Test, Unreal Tournament 3, Lost Planet, and Crysis. We also set up an ASUS P5K motherboard and a EVGA 780i to see how the Skulltrail's CrossFire and SLI performance compares to dedicated motherboards.

System Setup: Intel Core 2 Extreme QX9775, Intel Core 2 Extreme QX9650, Intel Core 2 Extreme X6800, Intel D5400XS, EVGA 780i, EVGA 680i, Asus P5K, 4GB FB-DIMM (2x2GB), 3GB Corsair XMS Memory (1GBx2)(2x512MB), 750GB Seagate 7200.10 SATA Hard Disk Drive, Windows Vista 32-bit. Graphics Cards: GeForce 8800 GTX 768MB, Radeon 2900XT 512MB. Graphics Drivers: ATI Catalyst 8.1, Nvidia ForceWare beta 169.28.

The matching Intel Core 2 Extreme QX9775 processor pair showed performance gains in most of our tests. The additional CPU didn't double framerates over the single chip system, but it did increase performance by a noticeable amount in Unreal Tournament 3 and Lost Planet. Crysis, on the other hand, illustrates the biggest challenge facing Intel. There just aren't a lot of multithreaded games that can scale up to four cores or more. Our dual-core Intel Core 2 Extreme X6800 performs just as well as the quad-core and 8-core systems in Crysis. We set up a second test that forced the systems to encode a video file using Windows Media Encoder 9 while running Crysis at the same time. In that test, the Crysis scores hardly budged, but the dual-QX9775 processor system had the fastest encode time of all the contenders.

Skulltrail is very much a luxury option for most gamers. The performance is outstanding, but with the current dearth of multithreaded PC games, eight processing cores might be too much hardware for pure gamers. However, coders and power-hungry media editors might just want to sit down with their managers to see if there's room in the budget for new workstations. Intel hasn't disclosed pricing for the board and processors, but we can expect a workstation-level board to retail in the $500 range. Each Intel Core 2 Extreme processors will likely sell for well above $1,000. Intel will announce pricing and availability when Skulltrail and the new Extreme processor officially launch in the first quarter of 2008.

What do you think of Skulltrail and the new Intel Core 2 Extreme QX9775?