BIOS And Overclocking
Asus has really done a nice job of refining the BIOS menus of the current revision of AMI's (American Megatrend) BIOS firmware. While most other mainstream motherboard manufacturers utilize Award BIOS firmware, Asus has engineered their own style of tweaks with AMI's offering.
The P5AD2-E comes with voltage modification options a-plenty. Users can adjust voltages for core CPU, Memory, FSB Termination and chipset core voltages with a wide range and good granularity of voltage steps. These options will obviously help overclocking for CPU and Memory Timings, which of course can be adjusted along with the PCI Express clock as well. We're not certain how useful overclocking the PCI Express links would be but the option is still there. In addition, Asus also offers their "PEG Link Mode" setting in this BIOS, which simply put is modest GPU and Memory Graphics card overclocking via the BIOS. For example, when set to auto, the default core speed of our GeForce 6800GT was set to 360MHz, whereas 350MHz is the actual stock speed for this GPU. For testing purposes, to keep the playing field fair, we set the PEG Link Mode setting to "normal" and then used NVIDIA's clock timing settings with the Coolbits registry tweak, to lock the GPU and Memory speeds to a stock 350MHz/1GHz configuration.
Finally, in addition to other standard issue settings, like DDR2 DRAM CAS/RAS Latency timings (and a host of divisor settings too!), Asus also offers other innovations in Health Monitoring functions and control in the P5AD2-E's BIOS. We especially like the "CPU Target Temp" setting along with "Q-Fan", which throttles the CPU cooling fan up or down, depending on load and the current temp of your CPU. Set the target temp lower and the CPU fan will spin faster until the target temp of your CPU is reached.
All told, the P5AD2-E's BIOS has just about anything an enthusiast could want in a high end motherboard BIOS. You can tweak to your hearts delight... or at least until you hit a non-bootable config. In which case, just hold down the insert key and cycle the power, and the board comes right back up with default CPU and Memory settings.
With a BIOS like this, you can imagine we had some fun overclocking the P5AD2-E. We took the simple objective of trying to hit the highest stable overclock on the CPU on our Prescott core Pentium 4. Then, we plugged in our Pentium 4 Extreme Edition 3.46GHz CPU and tried our hand with Asus' software overclocking tool called "AI Booster".
Our 3.6GHz Prescott core, set to its default multiplier hit 3.9GHz. This is about as fast as this CPU has ever hit on any board under any condition, so we'll chalk that up as a solid success for this motherboard. In addition our 3.46GHz P4 EE chip hit 3.8GHz with Asus' AI Booster utility. The CPU was stable for hours of folding, which is an excellent end result using only our stock Intel HSF.