How will PCs BIOS get replaced by UEFI

Lets talk about How will PCs BIOS get replaced by UEFI.

You all must have heard about your PC’s BIOS sometime or the other, if you have ever used a computer or owned it. But many of us do not exactly know what it is, or exactly what it does. There are chances that UEFI’s is going to take the place of the current PC’s BIOS, so lets have an overview as to what these two technologies are.

Basic Input/ Output System: Understanding the BIOS

BIOS, or Basic Input-Output System, are a one of the key components of a computer. It’s very low level software. It’s an integral part of the motherboard, and resides on a chip that is built on the motherboard. It is very important software. The job of the BIOS is, upon the starting of your computer, it wakes up various components and makes sure that they are performing in a proper manner. Once this is confirmed, the control is passed to a component of the Operating System – The Bootloader. Long time back, the computers had different ways to perform this operation, which was pretty different and was proprietary. But with time, the IBM’s 5150 slowed became the standard, over which the hardware compatibility was based. The Intel 8088 processor was used, which was a 16 bit processor, and hence the BIOS was also 16 but, which allowed an address space of 1MB. A Master Boot Record (MBR) was also used, which basically specified the computer’s partition table, which actually told the BIOS as to where the operating system is located.

POST is a process which is governed by the BIOS. The validity and the proper functioning of the components were checked using this Power On Self-Test. An error is displayed, or a cryptic series of beeps are heard, if some problem occurs during the test. Another acronym CMOS is used widely. It is simply used to refer to the battery backed up memory, which is used with the non-volatile RAM, which is in turn used by the BIOS. The accuracy of this term is not valid anymore, as in the present system; the method has been replaced by the flash memory, generally referred to as EEPROM.


It is a good system anyways. It gave the user the options to enable or disable various components and access to some advanced optional related to hardware. The new developing hardware made the BIOS obsolete, as is the trend in silicon world. There were several shortcomings and various negative comments. To overcome these several extensions were developed. The best example for this would be the ACPI, or the Advanced Configuration and Power Interface. It’s main function was to help with the configuration of the devices and with the advanced functions of the power management. But, with time, the limitation of the system had to be beaten by a new system.

The Future: UEFI

The Unified Extensible Firmware Interface, or UEFI (pronounced as ‘oofy’, or “U-effi’) has been developed by Intel, to solve the problems associated with its 64 bit Itanium based servers. With time, it was renamed to the Unified EFI Forum from the Intel Boot Initiative. Now, the Unified EFI Forum has the rights on the specifications for it. The pre boot environment has been seen to have undergone various major changes, which are brought by the UEFI.


As we already know, MBR’s are limited to only 4 primary partitions, with a size constraint of 2.2TB on the boot disks. UEFI again have a different case here. The partition table used by the UEFI is the GUID Partition Table. It has the power to utilize Globally Unique IDs, which are used to address the partitions in the system, and extends the size constraints to 9.4ZB on the booting drives. To realize the difference between TB and ZB, remember that a terabyte, or technically a tebibyte is 1024GB, whereas a zettabyte, or technically a zebibyte is 1024x1024x1024GB. I hope the difference; or rather the power can be realized. I guess, it really makes this technology future proof. This is not the end of the benefits. UEFI also allows more boot options than the BIOS. It doesn’t prescribe an exact file system. The network booting capabilities are really excellent. The OS Bootloaders can also act as an extension to the UEFI’s, which ultimately leads to function as a Bootloader by itself.

Graphics and Visuals

The new EFI is almost similar to the old BIOS, but some other EFI’s have changed their visual layout is a great way. The options of, such as overclocking, have been depicted using pictures, though it doesn’t really make it necessary, but in some cases they prove to be good. Let’s see one of the screenshots below:


It seems that the new layout is pretty easy to use, and is mouse capable. This shows it has a lot of potential in it.


Guess what MSI calls its version of EFI – It calls it the EFI Click BIOS.


The older extensions such as the ACPI’s, which are not dependent on the runtime environment such as on 16 bit, are supported by the UEFI. The beep codes are also a memory in the past. Extensions have a better way to test the components, until you are out of your luck and you have a bad processor. In addition, the manufacturers to add some more functionality, due to its support of EFI based partitions on the hard disks. A good example would be the Asus’s Splashtop instant on Operating System. A better boot time and loading is offered by the UEFI’s for such a system, though BIOS would also work as well.

The Game of Bits: 16 bit, 32 bit and 64 bit

As we have already seen the limitation of the BIOS to only 16 bit processor, and hence a memory addressing of 1MB, the UEFI has a different scenario. It is not constrained as the BIOS are. It has the power to functions at 32 bit or 64 bit modes, which generates the opportunity to access a lot more RAM’s by more complex processes. It also has a power to be architecture dependent. It provides drivers for several components which are again independent of the type of CPU you are using.

BIOS to the UEFI

UEFI is promising just because of its potentials. It operates at the level of BIOS, so the manufactures have already started to use it more and more on their motherboard, though everything is still not so optimal. The older visual style may be used, and the older extensions might be utilized with the new systems, until and unless the new systems are taken over by the newer systems. The pace at which this transition is occurring is pretty fast over the past few years. But applying UEFI on BIOS based motherboards is not possible. But there are odds that in the next years when you buy a new system or perform an upgrade, you will be making a switch, which you might not even realize. The switch is inevitable, though it is slow in the present days.

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