CSM Vs. UEFI – All The Differences Clarified Briefly 

While you are thinking about booting your computer, both the terms CSM and UEFI are widespread. But there are huge differences between these two. So to say, they are entirely the opposite roads to take while booting. 

So, in the case of CSM vs UEFI, CSM is an interface mode in the BIOS boot option that you can find in earlier Windows. On the other hand, UEFI is a modern solution used in all the updated PCs. It’s more like a modern BIOS version, ensuring more security and convenience. 

We have to dive deeper to let you know more about these two. So before you get confused, let’s have it all together! 

CSM Vs UEFI – All The Distinctions And Details 

Before we get into it, we need to know what these terms mean individually. So, now we will share an idea about that. 

What Is CSM?

The complete form of CSM is the Compatibility Support Module. In your PC’s boot mode, you will see the CSM if you have an older motherboard. While your PC is on the upgraded UEFI system, you can switch to the legacy BIOS using CSM. 

So basically, the CSM creates an environment in your PC that lets you boot the PC despite being on the UEFI firmware.

What is UEFI?

UEFI is the Unified Extensible Firmware Interface. Instead of BIOS, modern computers are using this interface. UEFI offers fast booting alongside user convenience. If you know the difference between BIOS Vs UEFI, you can understand it better. 

A core relationship between CSM and UEFI helps you to still legacy boot the PC while you have UEFI firmware installed. The CSM support lets the PC get into legacy mode to boot the PC still.

CSM Vs UEFI – The Core Differences 

Feature  CSM UEFI
Firmware Speed 32-bit speed 64-bit speed
Disk Partition Type MBR GPT
TPM Compatibility Not supported  Supports TPM
Disk Bootable Support up to 2 TB up to 9 ZB
Work Mode Character User Interface system Graphical User Interface system
Security  Less secured More secured 
Booting Speed Slow  Fast 
Booting Process  Simple  More detailed and secured 
Programming Language  Complex and requires more programming  C language, requires less programming to function 


We will look further into the differences between these two offers to know all about them. Let’s dive in! 

Disk Partition Type: 

One of the main differences that you will find between CSM and UEFI is the disk partition type. UEFI mode has the GPT disk partition, whereas CSM uses MBR. 

Using the MBR, the CSM support allows the creation of a legacy environment in your computer; therefore, the UEFI boot can happen. Besides, as the UEFI can run up to 8 ZB size disks., you get a massive advancement in system loading without a hassle. 


TPM Compatibility:

TPM is incompatible with legacy and CSM modes, but UEFI supports it. With the TPM, the UEFI increases the secured boot of the system that CSM or your legacy BIOS setup fails to offer. 


Disk Bootable Support:

CSM offers up to 2 TB bootable support, far less than the UEFI, which offers up to 9 ZB disk management support. With the extra support, the booting is much faster and user convenient with UEFI boot mode.


Work Mode:

The CSM works in the Character User Interface system, whereas UEFI works in the Graphical User Interface system. In this case, due to the Graphical User Interface system usage, the UEFI is much easier to use and operate, adding to the user convenience. 



Undoubtedly, you will get more security from UEFI. Before booting the system, UEFI scans every file and uses several steps like PEI, DXE, BDS, and TSL. Still, it offers faster booting than the CSM. However, CSM does not go through everything, and the booting process is relatively straightforward. 


Booting Speed:

Again, UEFI blows our minds here. Despite being utterly secure with the booting, it offers a fast boot. On the other hand, the typical CSM legacy BIOS mode won’t give you a fast booting experience.


Our Opinion 

After looking into every aspect and functionality, we must say UEFI is the beast compared to the CSM unless you own a computer that’s too old or from your grandparents’ generation. All the modern PCs are thinking ahead of legacy BIOS compatibility using UEFI firmware for the best outcome. So, UEFI gets the crown, always! 

If you are still confused, here are a few of UEFI’s best functionalities:

  • Faster boot time that saves your time
  • More secure boot to keep your PC safe from malicious operations
  • Also, it supports more than 2 TB OS system boot partitions which is a great advantage
  • Moreover, compatible with more than four partitions 
  • More reliable than legacy BIOS boot mode
  • The firmware comes with more upgrades 
  • Lastly, you get to have more advanced options from it


Things To Know Before Using UEFI Instead Of The BIOS:

All Windows operating systems from Windows 8 have the unified extensible firmware interface instead of BIOS. So, in this case, you cannot go back to your BIOS setup even if you want to. But here are a few things to know before you start using UEFI:

1. You Can Have All The Advancements Of Modern Tech 

As BIOS has been outdated, UEFI is an alternative to that. You can say it’s more like a modern replacement with more suitable options and a faster booting approach. 


2. You Can Emulate The BIOS Setting

Many virtual platforms are emulating the firmware and using the UEFI-dependent operating systems. So, you can use your Windows operating system X even on a virtual machine through emulation. 


3. You Can Still Boot Using A Removable Media

You can go to the Boot Device option and choose any favorable device like a USB drive if you want to boot using removable media. This offers you the ability to use different mediums in the booting process. 


4. You Won’t Need Any Boot Loader 

Any boot loader like an EFI boot loader is no longer required to boot the system as long as you are using UEFI. The OS can do the task of a loader all by itself while you are using UEFI.


5. Accessing Your Hardware Information 

Sometimes the UEFI settings screen may not let you view the data about the hardware. It’s not a big deal because you can still view that using any system information options in Windows.


How To Access UEFI Settings On Modern PCs?

You can access the UEFI using two different ways. While accessing the low-level settings, you must access the UEFI using your Windows boot options menu. But you can also access the UEFI by pressing a key just like you access BIOS during the boot. 


Explore More About CSM And UEFI

Should I Disable CSM?

You won’t have to disable the CSM on your own for new and upgraded PCs as they come with default disabled CSM. However, if you have an older model, you need to disable the CS before you boot the PC.

Which Is Better, UEFI Or BIOS?

UEFI is an alternative to BIOS that you can find on all modern PCs. With all the advancements and faster booting process, UEFI is undoubtedly better than BIOS. 

Is Windows 10 UEFI Or Legacy?

If you want to know whether your Windows 10 is UEFI or BIOS, you have to follow the following steps:

  • While the PC is on boot, open a command prompt 
  • Check under the Windows Boot Loader section
  • If the path is \windows\system32\winload.exe then it’s on legacy BIOS
  • But if it is on \windows\system32\winload.efi then your PC is on UEFI 

Is It Possible To Change From CSM To UEFI?

If your PC system has an option for UEFI mode, you can change it from CSM to UEFI. But there needs to be a GPT disk partition to enable UEFI.

Does Windows 7 Support UEFI?

Yes, it does. But you need to browse to the boot file to access the UEFI in your Windows. 

Closing Talk 

We have reached the end of our discussion about CSM vs UEFI. Both are quite different in functionality and system, as you know in brief now. CSM is for old PCs which are outdated now. Modern PCs use the UEFI boot system to let you have all the updates. 

So as you know how to use the UEFI for your betterment, we hope you understand it’s not entirely different from BIOS. It’s a far better and more modern alternative system for BIOS that brings more advancements than before.


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