The arrival of a new Intel motherboard chipset isn't always a cause for much rejoicing. After all, Intel has a nasty habit of churning out new chipsets so fast the solder has hardly set on existing boards. But its new X38 performance chipset is a little different. For as long as it lasts...

Unusually for Intel, its outgoing high end chipset, the 975X, was a seriously crusty old critter. It's been kicking around for two years. Making matters worse, the release of its latest mainstream chipset, the P35, left the 975X looking even more pointless and outdated.

All hail the new king

A warn welcome, therefore, to the new X38 performance chipset. The most obvious upgrades over the 975X include official support for 1333MHz bus Intel processors along with the latest 45nm Core 2 chips and DDR3 memory.

Of course, the mainstream P35 already offers most of that. Moreover, the P35 has proven an extremely impressive performer at both stock and overclocked settings. So, why pay more for an X38-powered board?

For starters it brings full support for the new Core 2 Extreme QX9650 45nm CPU. The P35 only officially tangos with the cooking versions of Intel's new 45nm Core 2 chips. But really, it's all about the X38's northbridge chip.

Firstly, Intel claims it delivers improvements to memory performance courtesy of a revised memory snoop feature. In simple terms, memory snoop allows the caching of commonly requested data in the northbridge, thereby avoiding the need to fetch it from main memory.

Next up is support for the latest 1333MHz DDR3 memory. On paper, that gives the X38 an advantage over the P35 which tops out at 1066MHz. In practice, many P35-based boards cope just fine with DDR3 DIMMs running in 1333MHz trim. Then again, both of the early X38 motherboards from Asus and Gigabyte we have seen claim support for DDR3 memory up to 1600MHz.

What's more, the X38 retains support for DDR2, giving both board makers and buyers the option to stick with more affordable DDR2 memory technology until DDR3 prices begin their final descent from the stratosphere.

The X38 also sports a number of enthusiast-friendly features. Most notable is XMP or Extreme Memory Profile. It's essentially a set of ehnanced memory profiles designed to boost bandwidth with compatible memory DIMMs. If that sounds familiar it's because Nvidia's EPP initiative is pretty much identical.

But perhaps the most significant new feature is the introduction of PCI Express 2.0, a world first for any PC chipset. The headline feature for PCIE 2.0 is a doubling of the interconnect bit rate form 2.5GT/s to 5GT/s. That in turn means the effective bandwidth of a PCIE 2.0 graphics port doubles from 8GB/s to 16GB/s. The X38 northbridge sports a pair of 16-lane PCIE 2.0 slots and a full compliment of 32 electrical lanes.

Wherefore art thou, SLI?

That's a layout which can only mean one thing to PC enthusiasts: a pair of video cards linked together for multi-GPU graphics rendering. ATI's Crossfire multi-GPU technology is officially supported at launch. However, Nvidia prefers to keep tight control on its competing SLI platform. It's not currently compatible with the X38 and that's not something we expect to change.

But what about performance? We've had a butchers at both Asus' new P5E3 Deluxe and the X39T-DQ6 from Gigabyte. In combination with Intel's new QX9650 quad-core monster, the Asus in particular is a bit of a stunner.

Actually, the Asus is a bit of a stunner all round. It even boasts an embedded Linux OS that offers a quickbooting alternative to Windows for light web browsing and even Skype telephony.

But we digress. Record breaking performance numbers in all application types are what you can expect from any half decent X38 board. Our only reservation involves that age-old Intel bugbear, memory bandwidth. Even with DDR3 memory running at 1333MHz, our testing shows the X38 only just cracks the 7000MB/s barrier.

That said, both boards will support memory running much faster than that. Courtesy of Corsair's latest 1800MHz DDR3 DIMMs, we squeezed over 9,000MB/s out of the Asus.

Don't mention the X48

Finally, to bring the X38 story full circle, we should briefly mention rumours of the imminent arrival of the X48 chipset. There's no official word from Intel, but the scuttlebutt suggests it will be a minor revision that adds official support for 1600MHz bus chips and DDR3 1600MHz memory. According to reports, it could be out in as little as one month.

That said, the first X38 boards from Asus and Gigabyte already deliver 1600MHz bus support. At the very least that makes them excellent candidates for overclocking enthusiasts.

However, it's not guaranteed they will play nicely with any 1600MHz bus desktop processors Intel might launch in future. Anyone worried about X38-based boards becoming rapidly redundant might prefer not to pull the trigger for a month or two. Especially considering the likely £150-plus asking price of any X38 motherboard.

But whatever happens with the X48, one thing is for sure. Intel's Nehalem modular CPU architecture is rapidly approaching and with it a whole new platform apporach from Intel. Both the X38 and X48 are guaranteed to be toast in 2008.

Intel X38 key features:

Socket:
LGA 775

Bus speeds:
800, 1,066, 1,333MHz (some X38 boards also support 1,600MHz)

CPU support:
All Intel LGA775 processors including new 45nm chips

Memory support:
DDR2 up to 1,066MHz, DDR3 up to 1,333MHz (board implementatio dependent - some boards also support 1,600MHz DDR3).

Expansion highlights (minimum):
2x PCIE 16 graphics, 8x PCIE, 2x gigabit LAN, 6x SATA

Other:
Intel High Definition Audio, Intel Matrix Storage Technology, Intel Turbo Memory (optional)

Price:
Typically £150-plus for third party board based on the X38 chipset