Motherboard hardware is important, but it's only one part of the overall experience. The accompanying firmware and software interfaces govern how users interact with the board, whether it's to overclock the CPU, adjust fan speeds, or modify the multitude of other system variables made available by modern mobos. Let's start with the firmware, which offers a more extensive array of tweaking options than what you get in Windows.
Asus has devoted a lot of development resources to crafting the core firmware shared by all its recent motherboards, and the effort shows. The interface is slick, responsive, and well-organized. Thanks to the new UEFI standard, the interface has full mouse support—wheel included—and pretty decent graphics, all things considered.
The screenshot above depicts the default EZ Mode interface, which is really geared toward newbies. There isn't much you can do from this screen beyond changing the order of boot devices and switching between pre-baked configuration profiles. However, the shortcut button in the bottom left corner of the screen provides quick access to the most commonly used elements of the Advanced Mode, which is loaded with options and organized more like a traditional BIOS. If you prefer the old-school look, the firmware can be set to skip the EZ Mode and jump directly to the advanced interface.
I really didn't want to have to go off on a rant here, but this is important. The P8Z77-I Deluxe employs a "MultiCore Enhancement" feature that's enabled by default in the firmware revision currently available to the public. When the memory speed is changed manually, this "enhancement" takes the liberty of using the CPU's maximum single-core CPU multiplier for all-core loads.
Admittedly, the difference isn't huge; on a Core i7-3770K, the peak Turbo speed with quad-core loads jumps from 3.7 to 3.9GHz. While this practice may not rise to Lance Armstrong levels of cheating, it's definitely doping. Intel defines the behavior as overclocking. The feature also violates good practices for motherboard firmware. Modifying one system variable should never cause a change in a completely unrelated setting. Also, a motherboard should never overclock a user's system without their explicit consent. The firmware doesn't even provide a clear indication that CPU clocks speeds are being increased.
Asus has been surreptitiously "enhancing" CPU multipliers in various ways since the Sandy Bridge era, and we've had numerous discussions with the company about our reservations. This time around, that discussion produced a new beta firmware that provides clearer messaging about what the MultiCore Enhancement actually does. More importantly, the new firmware disables the feature by default. We hope the changes stick—and that they're applied across Asus' entire motherboard line.
If you'd prefer to take an active role in overclocking, the firmware has no shortage of options. The OC Tuner feature lets the board overclock the CPU automatically—this time with your permission—and clock speeds, multipliers, and voltages can all be tuned manually. I'm particularly fond of the ability to choose between defining a specific CPU voltage and applying an offset that increases (or decreases) the default by a given amount. Most of the values can be keyed in directly, which is much more convenient than scrolling through lists of pre-defined settings.
Along with a wealth of performance tuning variables, the firmware provides a nice array of fan options. Temperature-based speed control is available for the CPU and system fans, and users can set temperature and speed limits manually. If you're not completely obsessive about tweaking your system's acoustic profile, the Silent, Standard, and Turbo presets should suffice.
Want even more control over fan speeds? Install Asus' AI Suite software for Windows, which includes an excellent Fan Xpert app that allows users to drag three points along the fan speed curve for both the CPU and system headers. You can even run a quick test that logs the rotational speed as the fan ramps up from idle to full blast.
AI Suite is made up of numerous components that can all be installed individually, so it's easy to configure the software to meet your needs. As in the firmware, the graphical interface feels refined and responsive. The GUI has an attractive theme. All of the components look like they belong together, and the controls are intuitive. I've used an awful lot of motherboard software in the decade or so that I've been doing these kinds of reviews, and AI Suite is easily the best of the lot.
The TurboV EVO component of AI Suite serves up an auto-overclocking mechanism for the CPU in addition to manual controls if you want to get your hands dirty. The selection of options isn't as diverse as what's available in the firmware, but the only feature I really miss is control over the memory frequency. All the other important stuff, including per-core multipliers and various voltages, can be adjusted by the TurboV software. There's also a separate AI Suite component that unlocks access to the power circuitry, allowing users to tweak VRM variables like the load-line calibration and current limits.
AI Suite is so good that we used it for the bulk of our overclocking tests. We didn't hold back, either. Our Core i7-3770K CPU was strapped to a dual-fan Corsair H80 water cooler, and we added one of Asus' hot-clocked Radeon HD 7970 graphics cards for good measure. Those kinds of components are unlikely to find their way into typical Mini-ITX builds, but we wanted to see how the board held up when pushed to the limit. This is a high-end Deluxe model, after all.
First, we gave auto-tuning a shot. This mechanism ramps up clock speeds while testing stability. If the system crashes, the auto-tuner makes adjustments and tries again. Within just a few minutes, the board settled on a CPU multiplier of 48X, a base clock of 103MHz, and a CPU voltage of 1.35V. The resulting 4.9GHz CPU clock is a full gigahertz higher than stock, and the system was perfectly stable under a combined CPU and GPU load.
As it turns out, the auto-tuner did a good job of finding the limits of our CPU. When we tried our hand at manual overclocking, we managed to get the system stable at 4.9GHz (this time with a 49X multiplier and the default 100MHz base clock) but ran into application and blue-screen errors at 5GHz. Tweaking the voltages and load-line calibration settings did make the system more stable, but it also increased CPU temperatures to the point that the chip started throttling under load. 4.9GHz is still an impressive achievement, and it matches the highest clock speed this particular CPU has reached on full-sized ATX motherboards.