It hasn't technically been officially released yet, but Intel's powerful new Core i7 (a.k.a. "Nehalem") processor reached enthusiast Web sites this week -- and lived up to its hype as an impressive design that puts some essential Northbridge chipset features directly onto the CPU die. Unfortunately, you still need a platform to run it on, and the Intel X58 Express seems to be the only one available at for the time being.

In the rush to lay accolades at the feet of the Core i7, the X58 has been mostly overlooked. It's too bad, really, since as much as the Core i7 is changing the processor landscape, the X58 has done the same for chipsets.

Inside the X58

On the surface, the X58 Express and ICH10 Southbridge pair looks like a standard Intel chipset, supporting the new, larger LGA1366 Core i7 socket instead of the last four years' LGA775. But under the hood, a quantum change in Intel's CPU architecture means that the X58 is unlike any desktop chipset the company has ever produced.

The major change involves the Core i7 taking over memory management duties via an integrated memory controller -- the architecture long followed by AMD. The Core i7 includes an on-chip, triple-channel DDR3 controller, usurping the traditional role of the Northbridge and eliminating the middle step in communication from the CPU to the Northbridge to system memory and back again.

The Core i7/X58 combination allows for a direct link from the processor to the memory, requiring three DDR3 modules for optimal performance. This enables extremely low memory latencies and truly spectacular memory bandwidth test scores, but lowers the DDR3 voltage ceiling to 1.6 volts, as any higher and you risk damaging the processor.

Unfortunately, that puts the vast majority of high-end DDR3 kits out of the running, as these regularly employ higher voltages to increase clock speeds and drop latencies. Incorporating the memory controller at the chip level also means zero flexibility when it comes to memory type, and it's DDR3 or nothing for the Core i7/X58. Intel would need a new Core i7 revision, not just a new chipset, to add DDR2 support to the mix.

Apart from the memory link, the Core i7 passes data to the X58 Express chipset using a high-speed, bidirectional QuickPath Interface (QPI), which is Intel's response to AMD's HyperTransport and supplies up to 32.0GB/s of overall bandwidth. The type of processor also determines the speed of the QuickPath Interface, as the high-end Core i7 Extreme Editions sport a 6.4 GT/sec (gigatransfers per second) link, while the standard Core i7 features only 4.8 GT/sec of bandwidth.

The X58 also provides up to 36 PCI Express lanes, which support multiple-graphics-card configurations such as PCI Express 2.0 1x16, 2x16, and 4x8. This is a standard feature for any enthusiast-level chipset. Both ATI CrossFire and Nvidia SLI multi-GPU technologies are supported, but exactly how this will pan out on retail motherboards is a bit murky and may involve a Nvidia-certified BIOS. As with any new platform, expect some driver issues and growing pains with multi-GPU configurations.

The last step in the X58 Express chain is a 2GB/sec DMI data bus to the ICH10 Southbridge, which is a bandwidth specification that hasn't changed in a few product generations.

ICH10: The Legacy Hardware Terminator

The ICH10 Southbridge looks like a standard Intel design, but it too has undergone a few changes. The basics are all there, including twelve USB 2.0 ports, six PCI Express x1 ports, Gigabit Ethernet, six Serial ATA ports, Intel High Definition Audio, and optional Intel Matrix Storage Technology. But as with many Intel Southbridge chips, it can be more interesting to see which features are not present, rather than which are there.

The ICH10 Southbridge maintains the same basic functionality as previous Intel models, but like the ICH9, it dispenses with legacy hardware support for many devices. The ICH9 found with the X38/X48 chipset gets rid of features like a floppy drive connector, serial and parallel ports, and PS/2 connectors. This has created some ire in the user groups, especially enthusiasts needing to load RAID drivers via floppy. Now the ICH10 has gone one step further and eliminated Parallel ATA support as well.

To be fair, PATA has been a pseudo-unsupported Intel chipset option for a while now, but the company has incorporated it in its motherboards, even up to the Intel DX48BT2 Extreme. But Intel's latest X58-based DX58SO board gets rid of it altogether, leaving only Serial ATA for any internal storage device. This lack of what Intel determines to be "legacy hardware support" is a bit troubling, especially to anyone with an IDE CD/DVD-R drive, as you'll need a new SATA model just to install Windows.

Some manufacturers will be forced to add in specific chipsets to handle these missing duties, as with the Asus P6T Deluxe, which incorporates both PS/2 and IDE support back in. On the flip side, not having to worry about old-school interfaces has really streamlined the platform, and will make it much easier for like-minded motherboard vendors.

The Intel DX58SO in Action

So far, we've been able to play around with exactly one X58-based motherboard, the Intel DX58SO. This is part of Intel's Extreme line for enthusiasts, and features an all-black PCB and better-than-average overclocking features. Add dual PCI Express 2.0 x16 graphics, PCI and PCI Express peripheral connectors, four DDR3 slots (though six would be better), 7.1 HD audio, Matrix RAID support, dual eSATA ports, and a totally silent/fanless design, and you're looking at an impressive new platform.

Performance is excellent, compatibility is very good, and it's amazing how seamless the overall platform is. We didn't even notice any difference between setting up a standard Intel X38 or X48 system, with its traditional Northbridge, and the new Core i7/X58 combo, which shifts to a new processor package and an inside-the-CPU memory controller. Intel has made the transition without skipping a beat: The X58 even offers both Windows XP and Vista support.

The only issues that cropped up related to Intel's stance on legacy hardware and the sometimes-surprising lack of connectors. For those with a favorite PS/2 mouse or keyboard, old peripherals or printers needing parallel or serial ports, or even a not-very-old IDE DVD drive, Intel is telling you it's time to upgrade.