The BIOS on the Crosshair IV is both new and old. The layout is going to be very familiar, while there are a few new features under the hood.
As with all of the ROG boards, you have options in the Extreme Tweaker section to push the limits of your system and CPU. These are not your garden variety overclocking tools, but ones that take into account the change of sub-zero cooling, like the Extreme OV (over voltage).
The voltage controls are all direct input for quick adjustments. Even to return to Auto settings, all you have to do is type in "auto" and hit enter.
ASUS has also given you control over the LEDs on the board; you can adjust these settings directly in the BIOS.
Now, something that we have not covered in detail before are the fan settings. ASUS allows for some excellent control over the fans connected to their motherboards and the ROG series in particular. As you can see here, you get a couple of options on the Crosshair IV Formula. These are Duty and User Modes. Duty Mode is based on the system load, while user mode is more like a fully manual control.
Another feature that does not exactly fit into the rest of the review is the Gaming First feature. This is a form of QoS to ensure that your gaming packets get priority over your LAN connection. This when combined with a good gaming router can result in improved Pings and a subtle edge during online gaming or at LAN parties.
Overclocking the Crosshair IV Formula was pretty simple in terms of using the tools that ASUS provides. However, on the opposite side the AMD Phenom II X6 that we used did not want to cooperate. This CPU left us with a very low clock of 3.981GHz, only a 700MHz OC. When we tried to pump additional voltage into the CPU we found that it did not respond well to that with our limited air cooling setup.
AMD claims that you do not need extra voltage for a high overclock; however, when we tried the same OC with a lower voltage the system would not post. So we do know that the board is capable of much more than we are getting from the CPU we used this time around. We just do not know how much more.
You can see the validation for the i5 661 with the GMA HD here.
Of course, as this is an ROG board the Crosshair IV Formula is going to have the ASUS TurboV. We played around with this tool again to see what the Auto Tuning feature would bring us. It actually did not do too bad. From the auto tune under extreme settings we ended up with an OC that was just a hair under our maximum OC for the PII X6 CPU we used.
As with other ROG boards, the Crosshair IV Formula has the ROG Connect feature. This allows you to connect your Crosshair directly to another system via a USB cable and then to control/monitor the BIOS and POST behaviour of the board. Unlike the Maximus III Extreme, it does not feature the Bluetooth ROG connect feature, but this does not limit its use in anyway.
As all overclocking results are dependent on the hardware you use, your results may vary. Results of our overclocking tests are included in the performance section with the stock scores.
Important Editor Note: Our maximum overclocking result is the best result we managed in our limited time of testing the motherboard. Due to time constraints we weren't able to tweak the motherboard to the absolute maximum and find the highest possible FSB, as this could take days to find properly. We do however spend at least a few hours overclocking every motherboard to try and find the highest possible overclock in that time frame. You may or may not be able to overclock higher if you spend more time tweaking or as new BIOS updates are released. "Burn-in" time might also come into play if you believe in that.