BIOS options and tweaking software
Asus has been catering to overclockers and enthusiasts for years, so it's no surprise that even early P5Q BIOS revisions are stacked with tweaking options. These options are present in both the P5Q and P5Q3, whose BIOSes only differ when it comes to memory bus speeds and DRAM voltages.

Overclockers will certainly have no shortage of options to play with here, as front-side bus speed options go all the way up to 800MHz (3200MHz with quad-pumping taken into account). Core multiplier control is available, as well, in addition to a healthy array of memory bus speed options. The P5Q3 has a couple of additional options on the memory bus front, which makes sense given that DDR3 is already scaling to much higher speeds than DDR2.

Voltage manipulation is an important component of the overclocking equation, and the P5Qs are well-equipped in that department, too. You can feed up to 2.1V to the processor, and if undervolting's your thing, the CPU voltage can be dropped as low as 0.85V. Couple plenty of CPU voltage headroom with support for DDR2 voltages up to 3.08V and DDR3 voltages up to 2.78V and the P5Qs look like prime candidates for even extreme overclocking endeavors. And there's no shortage of chipset voltages to manipulate, either. Heck, you can even fiddle with the GTL reference voltage of the north bridge.

As one might expect given their wealth of overclocking options, the P5Qs enable all kinds of memory tweaking. The four most popular timing controls sit atop a very long list of additional options. We have no clue what most of them do, but the sheer volume of available timings is impressive nonetheless.

Unfortunately, fan speed controls aren't quite as encouraging. Sure, you can enable temperature-based fan speed control for the CPU and system fan headers, but there's no ability to set temperature targets or actual fan speeds. One would think, with so much time an effort obviously going into loading up on overclocking options, that Asus would be able to dedicate some extra development effort to BIOS-level fan speed control.

The P5Qs do pack a little extra love in their respective BIOSes, though. Asus has integrated a handy flashing utility alongside support for multiple BIOS configuration profiles. Users also have control over Express Gate—an embedded Linux operating system that runs off an onboard flash memory chip that's hooked into one of the ICH10R's USB ports.

Express Gate is far from a fully-functional OS, but it does provide web browsing, chat, Skype, and picture gallery applications. The OS also supports USB storage devices, making it easy to load up a flash drive with the latest BIOS and driver revisions before you set up a system—a handy capability if you don't have access to a second machine.

Asus has already announced plans to put Express Gate on more of its motherboards, and that's not a bad idea. However, with its current application payload, the OS is a little short on real world utility. It would really be useful if Express Gate integrated an NTFS-aware file browser for data recovery and maybe even a disk imaging tool. Processor and memory stress testing applications would be useful for overclockers, too.

The P5Qs come with Asus' usual assortment of AI Suite and PC Probe overclocking, tweaking, and hardware monitoring software for Windows. There's nothing fresh on that front, but Asus has whipped up a new utility to control its Energy Processing Unit (EPU). This Six Engine app monitors wattages and tracks reductions in CO2 emissions, should you want to impress (or frighten) Prius drivers with your system's carbon footprint. More importantly, it allows users to switch between various energy saving modes to reduce system power consumption.

Six Engine looks impressive on the surface, offering four different operating modes. One of those modes is a turbo configuration that overclocks the processor, so it's not terribly useful from an energy savings perspective. The medium setting isn't that appealing, either; it resorts to throttling the front-side bus speed (down to 1200MHz with our 1333MHz FSB CPU) to conserve power, even when the system is under load. The low power mode is even worse, using a slower front-side bus speed and locking the CPU multiplier at its lowest available value, reducing a Core 2 Duo E6750 that should run at 2.66GHz to a lowly 1.8GHz. If you don't want to sacrifice performance for power efficiency, you're left with Six Engine's high performance mode, which is the only one that doesn't monkey with multipliers or bus speeds.

We're all for aggressive power saving schemes, but we don't really see the point of Six Engine's medium and low power modes. Intel's SpeedStep and C1E Enhanced Halt State already manipulate clock speeds to conserve power, and they at least do so intelligently so as not to impact system performance.

Specifics on specifications
If you prefer to peruse motherboard specifications in chart form, we've whipped up a handy specifications sheet for the P5Q and P5Q3 Deluxe below. Enjoy.