Author: Carl Poirier
Editor: Howard Ha
Publish Date: Monday, June 13th, 2011
Originally Published on Neoseeker (
Article Link:
Copyright Neo Era Media, Inc. - please do not redistribute or use for commercial purposes.

The Unified Extensible Firmware Interface (UEFI) is meant to be an OS-Firmware interface, much like a standard BIOS is. This interface manages the PC boot and runtime services. It has been developed from the ground up, and thus should not be considered as an evolution to current existing BIOSes, which did not end up evolving much with current hardware. There were many limitations that led to its development; most importantly, the 16-bit processor mode and the maximum 1MB of addressable space deeply rooted into traditional BIOSes. This is because the original BIOS was designed off of the IBM 5150, equipped with an Intel 8088 processor. Heck, this 16-bit chip is now over 30 years old!

More recently, hard drive manufacturers have exceeded the 2.2TB size limitation of the Master Boot Record (MBR) partition scheme of our blue friends, so this also needed a replacement.

It all began in 1998 when Intel created the Boot Initiative (IBI) program, which eventually led to the release of the Extensible Firmware Interface (EFI) version 1.10. Later in 2005, the Unified EFI Forum was formed as a non-profit industry-wide organization with the goal of promoting adoption and continuing the development of the specification, starting from what Intel had already developed. This forum board of directors includes representatives of many big players in the industry, such as AMD, American Megatrends, Apple, IBM, Intel, Microsoft, and more. There is no cost associated for hardware vendors to implement the UEFI specification in their products. Today, UEFI is now at version 2.3.1, approved in April 2011.

So, to solve the addressable memory and processor mode limitations, the UEFI is made to support 32-bit and 64-bit mode. In 64-bit, it can access the entire memory of the computer. Additionally, as of version 2.3, there exists bindings for all of these architectures: ARM, Itanium, x86 and x86-64. As for the hard drive capacity limitation, the MBR was replaced with a Globally Unique Identifier Partition Table (GPT), allowing for capacities up to 8ZiB (Zebibyte that is). Considering such a unit is 1 billion times bigger than a Terrabyte, how long will it be before the new limit is reached? If the capacity is multiplied by a factor of 10 every 5 years, roughly, it should take approximately half a century. It's difficult to predict where computers will be in 2060, however. Maybe Moore's Law will come to an end at some point? Maybe the quantum computers will take over?

Another major difference with traditional BIOSes is the support for graphical menus and features. No user interface is defined in the UEFI specifications however, so it is up to the hardware vendor to implement one of their own. ASUS is one of the manufacturers to have done so. The result is called the "EZ Mode" of the UEFI BIOS. One important thing to note here is that it is still being referred to as a BIOS, which it is clearly not, but for the the average consumer it is going to cause much less confusion. So from now on, it's going to simply be called an UEFI. In the next page, Neoseeker is going to take a look at ASUS' particular implementation.

Upon hitting the Delete key on the keyboard during boot, one gets to the main screen of the UEFI - or the EZ mode. Critical information such as the processor speed, memory size, temperatures and voltages can be consulted right away. Most importantly however, the appearance is aesthetically pleasing. Its blue-ish color scheme is easy on the eyes, and much less agressive than the sharp blue of traditional BIOSes. Another thing one will quickly notice is the mouse cursor, if a mouse is plugged in of course. Each and every setting can be set using either the mouse or keyboard.

In the section labeled "System Performance", one can choose a power profile. In the "Boot Priority" section, the boot devices can be reorganized. In the screenshot below, the hard drive is currently being swapped with the disc drive, using the mouse.

At the bottom, there is the Boot Menu, allowing a temporary overriding of the boot order.

At the top right, there is another menu for either exiting the UEFI, or entering the Advanced Mode.

Upon getting in the Advanced Mode, a menu that looks the same as the classic American Megatrends BIOS comes up. In fact, as indicated at the bottom, it looks like this part was developed by AMI as well.

One new thing has appeared in the Boot section however: the Setup Mode. This option can set either Advanced Mode or EZ Mode as the default interface displayed after hitting the Delete key during boot. Of course, one can always switch to the other later via the appropriate menu. Honestly, it proved to be a critical feature for the purpose of this review on the ASUS UEFI; the EZ Mode is great, but in the end it is not very useful for power users, and having to switch to Advanced Mode every time would have been a huge pain, especially under special circumstances like running out of a supply of liquid nitrogen.

The ASUS EZ Flash 2 and O.C. profiles are still present:

Finally, the Exit menu has the standard exit options and the option to switch back to EZ Mode. As for the EFI shell, it can be used to run some EFI applications. In fact, an UEFI could even access the Internet and update itself automatically, or even provide some entertainment with games or multimedia.

Overall, the ASUS UEFI is definitely a change for the better. Of course it overcomes the aforementioned problems with the classic BIOS, but it does so in an elegant way, in my opinion, by implementing a full UEFI, compared to Gigabyte's own solution which ended up being an EFI bootloader slapped onto the existing BIOS (though with support for hard drive capacities of 3TB and more). Gigabyte's solution gets the job done, but sooner or later, it's going to need the full installment of the UEFI. Of course, there is no mouse support in this Hybrid EFI, as Gigabyte calls it. Instead, the Touch BIOS was developped, which is merely an application running on a Windows operating system, whereas ASUS' UEFI is actually OS independent.

The UEFI still keeps the same BIOS menus as before, instead putting them into the Advanced Mode, so as to not disappoint users accustomed to the the AMI BIOS and of course the overclockers in need of the fine tuning options. The UEFI can still be navigated entirely using the keyboard, exactly like the AMI BIOS. The UEFI also has the option for starting right away in Advanced Mode, so all in all there is absolutely no downside of moving to UEFI.

In a few words, the ASUS UEFI is awesome for being aesthetically pleasing, simple and exaustive at the same time. Everyone should just be hoping that other manufacturers follow the same path soon. As of now, the only other manufacturer that has implemented UEFI is MSI. Maybe its Click BIOS, as it calls it, will be the subject of a future article. ASUS has raised the bar high for others to reach, though.


Copyright Neo Era Media, Inc., 1999-2014.
All Rights Reserved.

Please do not redistribute or use this article in whole, or in part, for commercial purposes.