The BIOS is a fairly standard affair, for the most part. The first few screens are typical from just about any motherboard, with the below left image showing the main screen, and the below right image showing the "Standard CMOS Settings" page.
The below left screen shows the "Advanced Chipset Features" screen, while the below right image shows the "Integrated Peripherals" screen.
Below we have the "PC Health Status" screen.
Things get a bit more interesting on the "Performance Options", and the remaining four screen shots are from this screen. The below left image shows that access to memory timing and clock settings, as well as CPU clock settings. The below right image focuses on the memory clock speed, and shows that you can manually adjust the speed from 400 MHz up to 1300 MHZ, a decent range of frequencies.
In the next screen we similar controls as found on the memory, but this time you can manually adjust the frontside bus from 800 MHz up to 1300 MHz, again another decent spread. The final screen shows that you can manipulate the PCI Express frequency if you want, too.
Although not shown, there are also settings for CPU and DDR2 voltage, which can be increased manually to help you reach the high overclocks.
In the BIOS section, we saw that the settings are definitely there for overclocking adventures. My experiences proved to be less impressive than I had hoped. The D840 processor overclocked to 840 MHz frontside bus, which is really only an increase from 200 MHz to 210 MHz clock speed. I have seen others that have been able to go all the way to 250 MHz with the same processor on this board, so good things are possible! The memory also didn't get very far (about 700 MHz from 667 MHz stock), and the timings had to be relaxed in the process, providing a net gain of nothing in performance testing... some faster DDR2 is definitely in order for this system!