As computers evolve to new heights, so must the systems that allow them to work properly. I’m sure many of you have heard of BIOS, and if you have used it in the past, then you should know it can sometimes be difficult to configure and use. This low-level software has remained almost unchanged for the last two decades, and because of this, it is now becoming outdated and un-supportive of new technologies.

A new system, called UEFI, is here to take its place, but like most new technologies, its implementation is slow and expensive. Users tend to overlook the importance of the low-level operating system, keeping true to the belief that “if it’s not broke, don’t fix it”. BIOS is reaching the end of its powers and new technologies are not supported any longer by this system, and this is what UEFI tries to fix. We hope this article will shed some light on the matter.

What is BIOS


BIOS stands for Basic Input/Output System, and what it represents is the low-level software that comes between the hardware of your computer and the operating system. It is the first thing to run when you turn on your computer and its purpose is to test the hardware and load the bootloader and operating system of your computer.

Every motherboard has a BIOS which can be handy in a number of situations. Thanks to the fact that it is independent from the operating system, users can access the BIOS with no operating system installed and with a minimum of components. More advanced users can also modify different settings available in the BIOS menu, such as clock speed, memory latency and several others. This allows tweaking a computer to get optimal performance, but this shouldn’t be attempted by inexperienced users, because any mistake made here can cause permanent hardware damage.

What is UEFI?

uefi vs bios

UEFI, or Unified Extensible Firmware Interface is based on a technology developed by Intel, and over the last couple of years, it has been gaining more attention, as computer manufacturers are starting to install it on their devices instead of the old BIOS. As you might have guessed, UEFI is the successor to BIOS, and slowly but surely, it will take over the market as the pre-installed boot system. It provides legacy support for BIOS functions and on top of that, many other features that makes it better suited for today’s computers.

While the UEFI system has major improvements over BIOS, it is still somewhat restricted due to the processor architecture. 64-bit processors have full support for UEFI systems, while x86 processors will have partial or no support and the OS must emulate a BIOS environment for them to work. When this happens, many of the extra features are lost. Microprocessor manufacturers and operating system developers have been working together to eliminate this problem, and to some extent, they have succeeded. Apple, Intel, AMD, Dell and others have given a lot of thought to UEFI implementation, and Microsoft also has added full support for UEFI in Windows 8.

Which technology is better to use?

uefi and biosThe older BIOS  has been the industry standard for 20 years, but in this time it didn’t see too many changes, being severely limited by its 1 MB of memory, 16-bit instructions and MBR (Master Boot System) partitioning system which supports a maximum of 2 TB hard drives with only 4 partitions. While this was far more than anyone would want 20 years ago, when put up to today’s standards, BIOS is seriously lacking.

Also, due to the number of technologies that are available now, and will be available in the future, the need for flexibility has never been greater. Loading device drivers, boot information in 1 MB of memory is a challenge even on its own, but with more and more devices making their way out of designer’s minds and into the real world, it most definitely will now be enough.

Here is where UEFI steps in. This system has a modular design, can support 128 partitions and a whopping 8 ZB (that’s zettabytes) of hard disk space thanks to the newer GPT (GUID Partition Table) system it uses. But the improvements don’t stop here,  as UEFI provides closer integration with the operating system, as seen with the Advanced Startup Options from Windows 8. Secure Boot is another UEFI feature that helps with security. It allows users to install only registered operating systems.

Each OS has a key integrated in its bootloader, and the UEFI system reads that key and compares it to a database stored in its memory. If the key is not present in that database, it won’t let you install that particular OS. To some, this might be disadvantage, as some Linux distributions might not be supported. However, the is a workaround, as UEFI allows users to manually add a new key to the database and install the OS they want. One operating system that has Secure Boot permanently locked with no possibility of adding a new key is Windows RT.

Thanks to the modular design of UEFI, new functionalities can be added later on and extend the system as computer hardware advances. This makes the system more futureproof, a feature that BIOS didn’t quite have. Furthermore, ease of use has been drastically improved in UEFI systems. If you’re familiar with the BIOS system, then you know it can sometimes be difficult to navigate and set up.

uefi bios chip

Newer UEFI systems use a specialized GUI which sometimes allows the use of the mouse. This makes it easier to navigate and configure, looking more like a regular operating system than a pre-installed firmware. Also, motherboard manufacturers can implement different software modules in UEFI which allow the user to test different hardware components easily.

Overall, the UEFI system is superior to the old BIOS thanks to its modular design, ability to be upgraded over time, independent CPU drivers and architectures and ease of use. It will be some time before UEFI permanently  replaces BIOS. As more and more manufacturers adopt the new system, and x86 CPUs are less used, the price for UEFI-enabled motherboards will be less and more users will buy them. This looks like the way of the future, but like with all advances in computing, it will require some time before it will become an industry standard.

Was this article helpful?