Verdict: Still the best nForce4 SLI motherboard money can buy

The A8N-SLI Deluxe had the distinction of being the first SLI motherboard on the market. Kudos aside, being first means that Asus has had more time than any other motherboard manufacturer to tweak the BIOS of its board in order to eke out every last drop of performance from the chipset. In fact, the latest BIOS, version 1006, is the fourth update Asus has made.

However, what really sets the A8N-SLI Deluxe apart (literally) from all the other nForce4 SLI motherboards that we've tested is how far apart its two high-speed PCI-E slots are spaced. The A8N-SLI Deluxe has two 1x PCI-E slots between its two 8x PCI-E slots, whereas just a single1x PCI-E slot separates the two 8x PCI-E slots of every other nForce4 board tested this month. Placing the high-speed PCI-E slots further apart means that there's far more space between the two graphics cards in SLI mode. It also means that Asus has had to design and manufacture its own extra-long SLI bridge connector, but the benefit of greater cooling to both graphics cards far outweighs this, especially if you're considering buying a pair of 6800 GTs or 6800 Ultras. It also provides a lot more room for bulky waterblocks or third-party HSFs.

However, the A8N-SLI Deluxe has more than just a thoughtful PCB design going for it - it has more I/O ports than you can shake a stick at too. Four S-ATA, four S-ATA II and two EIDE ports, all RAID-capable, mean you could potentially connect 6.4TB of storage to your system. On a more practical note, there are also eight USB 2, two FireWire and two Gigabit LAN ports. On-board AC97 audio is handled by the Realtek ALC850 chip, which supports 8-channel surround sound, a full set of analogue outputs, and both coaxial and optical S/PDIF outputs.

Unlike most motherboards, the A8N-SLI Deluxe is supplied with a full set of cables, so you can actually use all the I/O ports. Also included in the bundle are six Molex to S-ATA power converters and a game port on an external bracket. Another bracket allows you to connect two external S-ATA drives to your PC, although the S-ATA connector is so flimsy that we'd recommend sticking with USB 2 or FireWire-connected drives.

At the standard frequency settings, the A8N-SLI Deluxe performed almost identically to all the other nForce4-based motherboards. This is hardly surprising, considering that the memory controller is integrated into the Athlon 64 CPU, which makes it very difficult for motherboard manufacturers to differentiate their products' performance.

However, one way in which manufacturers can make their products different is by providing better overclocking and tuning options. And, if you dare to brave the multimenu, and somewhat overly complex BIOS of the A8N-SLI Deluxe, you'll find it's a very good overclocker.

By lowering our test CPU's multiplier, we succeeded in raising the FSB to 330MHz, which is considerably higher than most other motherboards in this Labs test, with the exception of the rather spectacular DFI Lanparty NF4 SLI-DR. Of course, you'd be lucky to overclock an Athlon 64 to 330MHz FSB while keeping it running at a decent multiplier even using phase-change cooling, but with Venice-core chips just around the corner, the overclocking headroom is very welcome.

Rather disappointingly, you can only raise the CPU core voltage to 1.55V, although this should be enough for a highly overclocked Winchester-core Athlon 64. Interestingly, although you can't change the chipset voltage, it already runs slightly higher than any other motherboard we tested: 1.6V rather than 1.5V. And, if you're feeling brave (or foolish) then you can choose to run 3V through the RAM - just don't blame us if your fancy DIMMs catch fire and melt through the PCB.

We've yet to see a bad nForce4 motherboard, which speaks volumes about the quality of the chipset, but the A8N-SLI Deluxe is still the best of breed. Admittedly, it's not the best overclocker - that honour goes to the DFI - but it's still leagues ahead of other SLI motherboards when it comes to physical design and features. The extra space between the two high-speed PCI-E slots means that it's easier to keep two cards cool, especially if you're going to replace the noisy Nvidia reference HSFs with Arctic Cooling Silencers or waterblocks. It's also one of the cheapest SLI motherboards that we've tested, and, amazingly, it's even cheaper than some non-SLI boards.

If you don't plan to buy a second graphics card to run in SLI mode then a cheaper board should suffice. But, as the A8N-SLI Deluxe offers much more upgrade potential for not much more cash, it's worth considering, even if you can't afford SLI. After all, you never know when a surprise pay rise will enable you to afford two stupidly fast graphics cards.

• Cases - 21st November 2008
• Motherboards - 24th October 2008
• Gaming Headsets - 26th September 2008
• Dream PCs - 24th September 2008
• Headphones - 12th September 2008
• Media PC components - 22nd August 2008
• PSUs - 14th July 2008

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