BIOS, Overclocking & Utilities
When it comes to the current "enthusiast class" highly configurable BIOS, Asus boards like the A8N SLI series have evolved to a level unsurpassed and equaled by a mere few in the market like Abit, DFI and MSI. The AN8 SLI Premium's BIOS menus are certainly no departure, and even the most tweak-crazed performance junkie will find the tools required within, to push the envelope nicely.
The A8N SLI Premium's BIOS options are wide-ranging and plentiful. CPU clock speeds and voltages, DDR speeds and voltages, Hypertransport link ratios, chipset voltages, all can be modified with a nice wide range of settings and good granularity. We do have a couple of small quibbles however. Asus' PEG Link (PCI Express Graphics Link) feature which is essentially a PCI Express Graphics card overclocking mechanism, with its rather ambiguous settings of Fast, Normal, Slow etc, doesn't really seem to do anything more than raise GPU core timings just a tad and shows no significant benefit on some graphics cards, like GeForce 6800GTs. In some cases, we've seen it cause some bugs with ATi based graphics cards affecting the otherwise superb stability of this motherboard. So, while it's really a unique added feature Asus brings to the table our advice is that users should shy away from PEG Link and if they are hell-bent on overclocking their graphics cards, use a utility like PowerStrip or NVIDIA's coolbits registry mod.
The other issue with the BIOS that is a bit misleading is that the memory speed settings suggest direct correlations in the memory clocks, when in fact they are multipliers or division off the main system, HT link and CPU base clock speed. For example a DDR400 setting would suggest an asynchronous 400MHz DDR speed, when in fact it's a 1:1 ratio based off the system clock, or in the case of a 225MHz system bus speed, you're looking at a clock double DDR450 speed setting although in the BIOS you have it set to "DDR400". A bit confusing for sure but we were able to work with the myriad of options in this menu area, like DDR333, 400, 433 settings and the like, all which correlate to different multipliers or divisors and not their listed speeds.
Other than that, the A8N SLI Premium's BIOS menu options are simply a top notch enthusiast class offering that will leave few wanting more features to play with. Two of our favorite features are the most simplistic. The board will automatically reset BIOS CPU and Memory timings to default settings upon repeated failed boot-ups, which really helps in finding that overclocking sweet spot. And you can always hold down the insert key on power-up as well, which effectively does the same thing. The other thing that is all too often unavailable in most BIOS options, is the ability for the board to boot from a mapped PS2 keyboard command. In the test lab, there's nothing like being able to just hit the space bar and power up. Macs have had this for years and years, why not PCs? The A8N SLI Premium does and it's a beautiful thing in all its simplicity.
Asus' AI Booster is a Windows based overclocking utility that will dynamically overclock the processor while under load. Users can choose between a 103%, 105%, 108% and 110% overclock. The utility also has integrated health monitoring functions in an attractive dashboard like interface. AI Selector on the other hand is a bit less novel in its functionality. It essentially just does what NVIDIA's Forceware drivers will do, enabling SLI or single graphic slot configurations from within Windows. The only bonus really is that AI Selector allows this functionality with a single mouse click and then a subsequent reboot.
Manual BIOS driven overclocking with the A8N SLI Premium turned out to be quite a productive effort and a whole lot of fun in the process.
In this test, we took the recently launch .09 micron Athlon FX 64 FX-57 out for some overclocking punishment. Although the remainder of our benchmark scores were taken with a stock speed Athlon 64 FX-53. Regardless, our test results speak for themselves. The A8N SLI Premium is a superb overclocker. We dropped the CPU multiplier to 12X, bumped the core CPU core voltage to 1.475, cranked the system bus (or HT link speed) to 258MHz, changed the HT multiplier setting to 4X and DDR speed setting to DDR333. The net timings were as follows: CPU clock speed 3.1GHz, HT Link speed 1032MHz, and DDR Memory speeds of 412MHz CAS2. This was easily the fastest we've ever seen an AMD processor run on air cooling. Incidentally, our CPU cooler of choice was a Zalman CNPS7700-Cu, which is a reasonably priced, high performance and very quiet copper CPU cooler.