EVGA's 122-CK-NF68 motherboard
Perhaps the most interesting element to the nForce 680i SLI's launch is the reference motherboard that Nvidia designed and is now manufacturing for the chipset. Nvidia has been doing motherboard reference designs for years, and recently partnered with Foxconn to bring its nForce 590 SLI for AM2 reference design to market as a retail product. This is the first time Nvidia has manufactured motherboards for sale to its partners, though.
EVGA is one of five partners that has bought into the 680i reference design; its board, the awkwardly-named 122-CK-NF68, is expected to start selling today. Despite the awful name, the board is pretty slick. Heck, it even looks good. Nvidia has dressed the design in black and blue, perhaps a hint at the bruising it hopes to give the competition.
As far as ATX layouts go, the reference design is nearly perfect. Power connectors are pushed out to the edges of the board where cable clutter won't interfere with airflow around the CPU socket or chassis exhaust, and the auxiliary 12V plug has eight pins for better power delivery. Of course, we should note that those with upside-down cases like Antec's P180 might have a hard time getting power cables to reach connectors located at the top of the board. The connector layout is optimal for traditional chassis that mount the power supply above the motherboard, but it's less than ideal for the small number of cases that mount the PSU below the mobo.
Those looking to run larger CPU coolers will be pleased to see that Nvidia has left loads of room around the CPU socket. The capacitors surrounding the socket are low-profile designs, and the board's passive VRM coolers shouldn't get in the way. Extremely large coolers may interfere with the beefy chipset cooler, but we haven't encountered any that do.
Still, we're glad to see the board shipping with silent chipset cooling. The monster north bridge cooler is linked via heatpipe to the board's south bridge, and in testing, we had no problems with instability or overheating. Nvidia does recommend using an included chipset fan for overclocking or water-cooled systems with little ambient airflow, though.
The chipset fan bundled with the board is actually pretty decent in size, and it's not obnoxiously loud. Hopefully it won't suffer the fate of smaller chipset fans that tend to develop an annoying high-pitched whine over time—a sort of shrill swan song before their inevitable and premature demise.
While we like the idea of an optional chipset fan, installing the fan is more difficult than it ought to be. The top nicely clips onto the heatpipe assembly, but there are two tiny screws that secure it to the base. I actually had to break out a specialty screwdriver similar to what you'd use for eyeglasses or watch batteries, and even then, the screws didn't want to go in straight. The fan still sits tight, but tapping the cooler for larger screws would make fan installation significantly easier.
Connector clearance wasn't always an issue with motherboards. However, with manufacturers squeezing an ever-increasing number of expansion ports onto boards whose real estate is fast becoming monopolized by larger graphics cards with double-wide coolers, clearance issues are now relatively common. Graphics card manufacturers have shown little desire to make their cards smaller, so it's been up to motherboard designers to carefully arrange ports to avoid potential conflicts.
With Nvidia a rather prolific manufacturer of extremely large graphics cards, it's no surprise that the nForce 680i reference design intelligently places IDE and Serial ATA ports where they won't interfere with double-wide coolers or longer graphics cards. The board's low-profile south bridge cooler also steers clear of graphics card conflict, and Nvidia has even relocated its two-digit post code display to ensure that it can be easily read even when a pair of double-wide graphics cards is installed.
SLI is currently limited to two-card implementations, but the 680i reference board nonetheless features three PCI Express x16 slots. The top and bottom slots each have a full 16 lanes of bandwidth, while the center is a physical x16 slot with eight lanes of electrical connectivity. Nvidia suggests that this center slot is perfect for physics processing, where an eight-lane configuration's 2GB/s of bandwidth should be ample.
Attention to detail is what really makes the nForce 680i SLI reference design stand out, and it's readily apparent when we take a closer look at the board's slot configuration. For example, the slots are organized such that a double-wide SLI configuration still leaves a pair of PCIe slots and one standard PCI slot open for expansion cards. The board also uses PCI Express retention clips that can easily be activated with one hand, even while usually cumbersome double-wide graphics cards are installed.
Around the backplane, the board offers a decent array of connectivity options, including a full suite of analog audio ports and a digital S/PDIF output. The Firewire port is powered by a Texas Instruments TSB43AB22A 1394a controller, and is the only onboard peripheral that doesn't stem from the nForce 680i SLI chipset. An additional Firewire port is also available via an onboard header, as are four more USB ports, and a serial port for legacy luddites.
Just about the only thing missing from the port cluster is external Serial ATA (eSATA) connectivity. Mobo makers usually slap an auxiliary Serial ATA controller onto their boards to feed eSATA ports, but you won't find competing SATA controllers here. Nvidia says all of the nForce 680i SLI's SATA ports are compatible with eSATA provided you have the proper cabling, though. Unfortunately, that cabling isn't included with the board.
