How to configure RAID 5 in BIOS?

What is RAID 5?

RAID 5 is a redundant array of independent disks (RAID) configuration that provides data redundancy and fault tolerance. In RAID 5, data and parity information are striped across all disks in the array. If one disk fails, the data on the failed disk can be rebuilt using the parity information on the remaining disks.

RAID 5 requires a minimum of three disks, but it is most commonly implemented with five disks. The key advantages of RAID 5 are:

  • Data redundancy – If one disk fails, data can be rebuilt from the remaining disks
  • Improved read performance – Data is striped across multiple disks, allowing for concurrent disk reads
  • Cost-effective – Only one parity disk is required, minimizing the storage overhead

The main disadvantage of RAID 5 is that write performance can be slow since parity information needs to be calculated and written with each write operation. However, RAID 5 provides a great balance of redundancy, performance, and efficiency for most applications.

Why Configure RAID in BIOS?

There are several reasons why you may want to configure RAID arrays in the BIOS instead of using operating system utilities:

  • OS independent – The RAID array will be available no matter what OS is installed.
  • Pre-boot accessibility – The RAID volume can be accessed during the pre-boot environment for operations like recovering data from a failed drive.
  • Ease of recovery – If the OS becomes corrupt or unbootable, the RAID array is still intact and accessible.
  • Compatibility – Some older operating systems lack good software RAID utilities. BIOS RAID ensures compatibility.

The main trade-off with BIOS RAID is that you lose some software RAID management features. But for many, the benefits outweigh the limitations. Configuring RAID through BIOS is recommended for simple RAID configurations that just need redundancy and improved disk performance.


Before you can configure RAID 5 in BIOS, make sure you have:

  • Motherboard with RAID-capable BIOS – Most modern motherboards support RAID configurations through the BIOS.
  • At least three compatible storage drives – For RAID 5 you need at least three identical drives. Hard drives, SSDs and in some cases NVMe devices can be used.
  • Backup of any important data – Configuring RAID will erase all data on the drives. So backup anything important first.
  • BIOS manual – Have your motherboard BIOS manual handy for specific instructions.

It’s also a good idea to confirm that your motherboard chipset supports the type of RAID you want to implement. The process will be very similar across different BIOSes, but always refer to your motherboard documentation for specifics.

RAID 5 Configuration Steps

Here is an overview of the general steps to configure RAID 5 through BIOS:

  1. Enter BIOS setup utility – Boot into BIOS by pressing the appropriate key during system startup. This is usually Delete, F1, F2 or F12.
  2. Enable RAID mode – In the BIOS, find the setting related to SATA or drive configuration and change the mode to RAID.
  3. Create RAID array – Locate the RAID configuration menu and choose to create a new array. Select RAID 5 as the RAID level.
  4. Select drives – Select the physical drives you want to include in the RAID 5 array.
  5. Configure array properties – Adjust any optional RAID settings like the stripe size.
  6. Save RAID config – Save changes to create the RAID 5 array and exit the RAID config menu.
  7. Exit BIOS – Save changes and exit BIOS. Reboot the computer.
  8. Check disk management – Once booted into the OS, check disk management to see the new RAID 5 volume.
  9. Partition and format – Create a partition on the RAID volume and format it with a filesystem like NTFS.

The exact steps can vary across motherboard manufacturers. But this covers the general workflow for configuring RAID 5 through system BIOS.

Detailed Configuration Instructions

Now let’s look at a detailed walkthrough of configuring RAID 5 on an example system:

1. Enter the BIOS Setup Utility

– Restart the computer and press the BIOS key during POST. This is usually Delete, F1, F2 or F12.
– You’ll enter the system BIOS setup utility. Navigate to the configuration menu.

2. Enable RAID Mode

– In the BIOS, find the option for SATA or onboard storage configuration. This may be called Onboard SATA Type or similar.
– Change the mode from IDE/AHCI to RAID. This enables RAID functionality.
– Save changes and continue to the RAID configuration menu.

3. Create a New RAID Array

– Often there is a dedicated RAID configuration menu. Go there to create the array.
– Select the option to create a new array. Choose RAID 5 as the RAID level.
– Give the array a name if the option is available.

4. Add Drives to the Array

– In the RAID configuration screen, select the physical disks to add to the RAID 5 array.
– Match the array size to the smallest drive capacity.
– Only identical drives can be used in a single array.

5. Configure Array Options

– Adjust optional settings like the stripe size. 64KB is common.
– Use default values if you’re unsure. The OS can manage the array after creation.
– Avoid initializing or formatting the array here. Do that later in the OS.

6. Save RAID Configuration

– Save the new RAID 5 config and exit back to the main BIOS.
– Reboot the system to apply and initialize the new array.

7. Check Disk Management

– Once booted into Windows or your OS, open disk management.
– The new RAID volume should be visible but unformatted.
– If not visible, ensure RAID mode is enabled in BIOS.

8. Partition and Format Volume

– Create a partition on the full RAID 5 volume.
– Format the partition with NTFS or another filesystem.
– The RAID 5 array is now ready for use as a data drive.

Verifying RAID 5 Functionality

To confirm your new RAID 5 array is functioning properly:

– Check disk management to ensure the array is listed and formatted.
– Make sure the available capacity matches your disk sizes.
– Write sample files to the array and validate redundancy.
– Temporarily disconnect a drive and reboot. The array should rebuild.
– Reconnect the drive and check that data integrity is maintained.

You now have a working RAID 5 array providing data redundancy! Be sure to backup the array regularly as RAID is not a replacement for backups. RAID 5 protects against a single drive failure but not catastrophic system damage or multiple drive failures.

Monitoring and Maintaining RAID 5

Here are some tips for ongoing management of your RAID 5 array:

– Monitor the health of the array with OS utilities like Windows Disk Management.
– Watch for warning signs like slow performance or increasing errors.
– Only use identical drives if expanding capacity.
– Have spare drives ready for quick replacement of failed drives.
– Backup the data regularly in case multiple drives fail.
– Consider a hardware RAID card for more advanced management features.

Overall, RAID 5 provides excellent redundancy with minimal overhead. Just be diligent about monitoring the array health and having backups available. Replacing a failed drive promptly will keep the array operational.


Configuring RAID 5 through system BIOS is a straightforward process that adds valuable redundancy to your storage system. The basic steps are:

  1. Enable RAID mode in BIOS
  2. Create a RAID 5 array
  3. Add matching drives to the array
  4. Configure RAID options
  5. Save config and reboot
  6. Partition and format the volume in the OS

Following your motherboard documentation for the specific BIOS menus and settings is key. But the overall workflow will follow this sequence.

With a properly configured RAID 5 array, you gain data redundancy and protection against single drive failures. Just be diligent about monitoring the health of the array and maintaining backups. Used wisely, BIOS RAID 5 is a valuable resilience tool for any storage environment.