You can use GPT and BIOS – there's some subtle differences. You will need to create an unformatted partition size 8M-32M (Calamares uses 32M) and this partition must be of the type BIOS BOOT (0xEF02). When you install the bootloader using GPT you must install to partition e.g. /dev/sdyX.When installing Windows*, the partition style used will determine if UEFI mode or legacy BIOS mode is supported. UEFI mode is compatible with the GUID Partition Table (GPT) partition style, while the legacy BIOS mode is compatible with the Master Boot Record (MBR) partition style.The disk must have an EFI partition to boot. You must have the built-in Diskpart.exe and Bootcfg.exe utilities to create bootable mirror volumes on GPT disks. You can do some of these steps with the Disk Management console, but others you can do only with the built-in Diskpart.exe utility.

Should I use GPT on UEFI : When you deploy Windows to a UEFI-based device, you must format the hard drive that includes the Windows partition by using a GUID partition table (GPT) file system. Additional drives may use either the GPT or the master boot record (MBR) file format.

What is GPT on BIOS

Master Boot Record (MBR) disks use the standard BIOS partition table. GUID partition table (GPT) disks use the Unified Extensible Firmware Interface (UEFI). One advantage of GPT disks is that you can have more than four partitions on each disk. GPT is also required for disks larger than 2 terabytes (TB).

How to change GPT to UEFI in BIOS :

1. Open "Command Prompt" with administrator privileges.
2. Issue the following command: mbr2gpt.exe /convert /allowfullOS.
3. Shut down and boot into your BIOS.
4. Change your settings to "UEFI mode."

GUID partition table (GPT) disks use the Unified Extensible Firmware Interface (UEFI). One advantage of GPT disks is that you can have more than four partitions on each disk. GPT is also required for disks larger than 2 terabytes (TB).

GPT and MBR disks can be mixed on systems that support GPT, as described earlier. However, you must be aware of the following restrictions: Systems that support UEFI require that boot partition must reside on a GPT disk. Other hard disks can be either MBR or GPT.

How do I convert GPT to UEFI

1. Open "Command Prompt" with administrator privileges.
2. Issue the following command: mbr2gpt.exe /convert /allowfullOS.
3. Shut down and boot into your BIOS.
4. Change your settings to "UEFI mode."

Caution: Converting a disk drive from MBR to GPT or conversely erases all data from the drive. Ensure that all files have been backed up to a different hard drive or storage device before following the instructions below.When NOT to use GPT

1. Reasoning OUTSIDE the code layer. An example of this is to use ChatGPT for answering questions about the Dialogflow Conversation Layer.
2. Using it at the wrong level of abstraction.
3. Repetitive, modular NLP tasks.

If you have a hard drive that you would like to use and it is 2 TB or smaller, select MBR when you initialize the hard drive for the first time. If you have a hard drive that you would like to use but not boot from and it is larger than 2 TB, select GPT (GUID).

Can I convert BIOS to UEFI : Open Command Prompt with administrator privileges. Restart the system and boot into the system BIOS. Change the settings from Legacy BIOS mode to UEFI mode.

Can I upgrade my BIOS to UEFI : Convert from BIOS to UEFI during in-place upgrade

It automates the process to repartition the hard disk for UEFI-enabled hardware. You can integrate the conversion tool into the in-place upgrade process. Combine this tool with your upgrade task sequence and the OEM tool that converts the firmware from BIOS to UEFI.

Is GPT better than MBR

Choosing the Best Partitioning Scheme

MBR is compatible with legacy and older operating systems that do not support GPT. On the other hand, if you have a newer computer with UEFI firmware, GPT is recommended for better compatibility and support for modern features.

Although both GPT and MBR work fine, to have a speedy Windows boot, GPT is the better choice yet again. And because you require a UEFI-based system for faster bootup, and UEFI only works with GPT partitioning. So once again, GPT seems the more logical option when it comes to MBR or GPT for SSD.Follow the simple steps to convert GPT to MBR:

1. Install and launch EaseUS Partition Master on your computer, go to the Disk Converter section.
2. Select "Convert GPT to MBR" and click "Next" to continue.
3. Select the target GPT disk that you want to convert to MBR, and click "Convert" to start the conversion.

How to enable UEFI in BIOS : Press F2 when prompted to enter BIOS menu. Navigate to Boot Maintenance Manager -> Advanced Boot Options -> Boot Mode. Select the desired mode: UEFI or Legacy.