For all intents and purposes, the C51XEM2AA is an nForce 590 SLI reference design. NVIDIA wanted to build a reference board loaded with overclocking options and enthusiast-friendly features, and Foxconn was eager to cooperate. The reference design was so solid that Foxconn actually turned it into a retail product as the C51XEM2AA-8EKRS2H, possibly the most awkwardly-named motherboard to ever pass through the Benchmarking Sweatshop.

The C51XEM2AA was designed to show off the nForce 590 SLI in all its glory, and the board does a good job of letting the chipset have all of the attention. Without extra peripherals and flashy coolers gobbling up board real estate, the C51XEM2AA also enjoys a rather spacious layout.

Unfortunately, the uncluttered layout isn't perfect. Again, we see an auxiliary 12V connector mid-way down the board just above the top PCI Express x16 slot. This location creates the potential for cable clutter between the CPU socket and rear chassis exhaust, so we'd prefer to see the auxiliary power connector up along the top edge of the board. To be fair, though, situating the connector halfway down the board improves compatibility with non-standard case designs that put the power supply below the motherboard rather than above it.

The C51XEM2AA does a good job of leaving loads of room around the CPU socket for gargantuan coolers. The DIMM slots are a little close, but that's the case with nearly every Athlon 64 motherboard. At least there's a little room for airflow between the two dual-channel DIMM slot pairs.

From this angle we have a good view of the board's tallish passive north bridge cooler. It's not a funky heatpipe design like the one found on the M2N32-SLI Deluxe, but it's every bit as silent. Unfortunately, the cooler only covers the north bridge; it doesn't provide any extra cooling to the board's VRMs. The passive north bridge cooler is also paired with traditional active south bridge cooling. We've found that tiny chipset fans develop an annoying, high-pitched whine over time, and while the C51XEM2AA's cooler has been reasonably quiet for us thus far, we don't hold out much hope that its noise levels will be acceptable 6-12 months from now.

At least the active south bridge cooler's a low-profile design. This ensures compatibility with longer graphics cards, although the C51XEM2AA's PCI Express x16 slot retention tabs are extremely hard to get to with double-wide graphics cards installed.

One of the Foxconn board's more appealing layout attributes is the fact that all six of its Serial ATA ports are accessible with longer graphics cards installed. That's surprisingly rare for a high-end enthusiast board, and it's nice to see NVIDIA and Foxconn paying special attention to this issue. Longer secondary graphics cards do make it a little difficult to read the board's two-digit POST code display, though. At least nothing gets in the way of the onboard power and reset buttons, which are buried in the bottom right-hand (lower left in the picture) corner of the board.

The C51XEM2AA doesn't think much of serial and parallel ports, but you'll find just about everything else in the port cluster, including digital and analog audio outputs and two flavors of Firewire. Interestingly, the board offers two more external USB ports than the M2N32-SLI, which doesn't fully tap the chipset's 10 available USB ports.

Foxconn doesn't include much in the way of extra goodies with the C51XEM2AA, but we should point out that all six of the Serial ATA cables in the box have right-angle connectors. That won't improve Serial ATA transfer speeds, but it can make for cleaner cable routing around a case's hard drive bays.