We’ve already described ASUS's very handy implementation of the UEFI standard in our previous reviews. The ASUS EFI BIOS interface offered a few special features and had a ROG-style design for the ASUS Crosshair V Formula model, but you won't find any differences between the M5A99X EVO and M5A97 EVO on one part and the ASUS Sabertooth 990FX on the other, for example. The two mainboards having the same BIOS options, we will use the M5A99X EVO in the following description.
By default the BIOS opens up in EZ Mode which gives you a lot of information but offers almost no user-defined options. You can only learn some basic system specs and monitor a few parameters, choose between high-performance and energy-saving operation modes, and define the boot device order by dragging the icons with your mouse.
You can make the BIOS open in Advanced Mode. In this case you will see the familiar Main section.
The BIOS interface is available in multiple languages, which may be handy for non-English speakers.
Most of the overclocking-related options are collected in the Ai Tweaker section. The new BIOS interface may seem unusual but its structure and setup options are quite recognizable as those of ASUS's older BIOS. There are a lot of new options, though, which are mostly related to power supply and the new digital power system called DIGI+.
You can control ASUS’s exclusive power-saving technologies right here. One of them allows changing the number of active phases in the CPU voltage regulator depending on load. CPU Load Line Calibration can now be not only enabled or disabled but also set to a certain level (it helps counteract the voltage drop occurring on the CPU under load). You don’t have to move to the monitoring section to check out the current levels of voltages as they are shown right next to each voltage-affecting parameter.
Some of the setup options are available in individual subsections in order not to clutter the main section. One such subsection contains memory timings, for example.
The options of the Advanced section should be familiar to you and their names are self-descriptive. We can only note that SATA disks work in AHCI mode on ASUS mainboards by default.
The CPU Configuration subsection reports you basic information about the CPU and allows to control some CPU-related technologies. Take note that all of the power-saving technologies are enabled by default. There is an option called HPC Mode that prevents the CPU from lowering its clock rate under load.
The Monitor section is where you can check out the current temperatures, voltages and fan speeds. You can select the speed regulation mode for the CPU and system fans: Standard, Silent or Turbo. You can also set them up manually (except for the Power Fan).
System startup options can be found in the Boot section. It’s here that you can change the start mode from EZ to Advanced.
Next goes the Tools section.
The integrated BIOS update tool called EZ Flash 2 is perhaps the handiest and most functional among the utilities of its kind. It has changed with the transition to EFI BIOS. For example, the current firmware version is saved into the root directory of the connected drive by default.
Like on mainboards from many other brands, we can now see the information written into the memory modules' SPD unit.
ASUS mainboards allow you to store and load up to eight profiles with full BIOS settings. Each profile can be given a descriptive name.
The Exit section goes last. It allows you to save your changes, load default BIOS settings, or switch back to EZ Mode.
New ASUS EFI BIOS is an excellent example of how the capabilities of the old BIOS can be expanded without making it harder to use. We guess the biggest problem that this BIOS presents is the sheer abundance of settings. However, the mainboard sets most of them at optimal values by default, so you can leave everything as it is and have your system running smoothly.
There are but few minor problems and inconveniences we can note. For example, the profiles with settings do not remember your turning off the startup picture and the current firmware is saved only to the disk's root directory rather than into any folder you want.