Abit AN8 32X - nForce 4 SLI X16
Board Layout (Continued)
Connecting everything together is nVidia's nForce4 SLI X16 chipset, the most popular high-end chipset on the market today. The nForce4 SLI X16 takes everything which made the original nForce4 SLI chipset so popular and expands upon it, offering true PCI Express 16 x 16 graphics card slots, specifically targeted for high-speed SLI graphics configurations. PCIe 16 x 16 isn't a unique feature to this chipset anymore, as ATI's new Radeon Xpress 3200 Crossfire now supports these speeds as well. Nevertheless, SLI is still by far the more popular of the two multi-GPU options on the market today, and high-end gamers are still flocking to the nForce4 SLI X16 chipset.
Powerful as it is, the nForce4 SLI X16 chipset also runs quite hot. The chipset is broken up into two separate chips, each of which supports a dedicated set of PCI Express lanes to utilize. The chips are cooled through passive methods using Abit's "Silent OTES (Outside Thermal Exhaust System), which works in conjunction with a heatpipe which helps move heat over the layout of the board. The Southbridge component produces the lion's share of heat, and its heat is routed through the heatpipe through a large blue heatsink on the top left section of the motherboard. This heatsink receives airflow from the outside of the chassis in order to keep this chip cool without the use of any chipset fans.
Without the use of fans, the board runs silently and will also be more stable over time, as there are no potential fan failures which can happen in the future. While the heatpipe runs nearby the motherboard's Northbridge chip, the heatpipe does not draw heat away from this chip, as the heat generated by this chip can be handled by a simple aluminum alloy heatsink. This is in contrast to Asus's passively cooled nForce4 SLI X16 motherboard design, which cools both the Northbridge and Southbridge chips with a dual heatpipe cooling system.
The board supports 2 x PCI Express x16 slots, both with dedicated 16x PCIe lanes to utilize. Abit has an interesting PCI Express graphics card latching system, which locks the cards into place with the use of tension-based plastic clips. The clips are alternating in position between the slots, as this placement method allows one to release the graphics card from the slots easier when the motherboard is installed in a system. Longer graphics card shouldn't have a problem on the A8N 32X, as the Southbridge heatsink and IDE ports to the right side are short enough that graphics cards will clear them.
The board supports two PCI Express x1 expansion slots for those dozen or so PCIe x1 peripherals actually on the market today. Also supported near the bottom of the board are two 32-bit, 33 MHz PCI slots for all your legacy peripherals. If we had our preference, we would have opted for an additional 32-bit PCI slots instead of PCI Express x1 (simply given the sheer volume of 32-bit peripherals vs. PCIe x1 on the market), but we can't complain too much here. We also would have opted to put the top PCI Express x1 slot between the PCI Express x16 slots, allowing for more airflow room between the PCI Express x16 slots for SLI configurations.
Riding under the last 32-bit PCI slot is an oddly placed 4-pin Molex connector, one of two oddly placed power connectors on this motherboard. This 4-pin Molex near the bottom of the motherboard is designed to provide an extra 12V boost to the PCI Express slots, which is recommended (for stability purposes) if you're using an SLI graphics card configuration, but is not explicitly required. The other strangely placed power connector is the secondary +12V ATX connector, which is placed between the I/O ports and CPU socket. It's far enough away from the socket that it won't get in the way of most coolers, but if your +12V ATX cable doesn't have enough leeway; it could become a nuisance in some scenarios. We're much happier when the +12V ATX connector is placed near the 24-pin connector on the right side of the motherboard.