What are the pros and cons of partitioning external hard drives?

Partitioning a hard drive means dividing it into multiple logical storage units called partitions (Disk Part, 2023). Each partition acts as a separate drive that can have its own file system, appearance and function. Partitioning is commonly done to organize data, separate operating systems, increase performance, or enhance security.

There are several reasons why people partition external hard drives (GigMocha, n.d.). The key benefits are:

  • Easier data organization – Partitions allow you to separate data types like photos, documents, music, etc. into different sections.
  • Protection from drive failures – If one partition gets corrupted, the others remain usable. This minimizes data loss.
  • Isolation of operating systems – Having separate partitions for OS files helps prevent instability and conflicts.
  • Enhanced performance – Partitioning can improve speed for certain workloads by enabling parallelization.
  • Extra security – Sensitive data can be isolated from other files for access control.

With these advantages, it’s clear why partitioning remains a popular practice today.

Pros of Partitioning

Partitioning an external hard drive has several advantages. The main benefits are increased organization, easier backups, and the ability to separate operating systems and data types.

Partitioning allows you to isolate operating systems onto their own partitions. For example, you can have one partition for Windows, another for Linux, and a third for macOS on the same drive. This lets you dual boot multiple operating systems without them interfering with each other 1.

Partitioning also lets you separate data types onto different partitions. For instance, you could have partitions for documents, media, software installers, and backups. This increased organization makes it easier to find, manage, and back up your data 2.

With everything compartmentalized into partitions, your data is much more organized and manageable. You can even set different partition sizes according to your needs, like a larger partition for media files and a smaller one for documents.

Cons of Partitioning

While partitioning a drive can provide some benefits, there are also some potential downsides to consider:

Partitioning requires completely reformatting the drive, which will erase all existing data. So partitioning is really only an option when setting up a brand new drive, or if you have already backed up all the data on an existing drive.[1]

The process of partitioning and managing partitions can also be complex for beginner users who are unfamiliar with disk management concepts. There is a learning curve involved in understanding partition alignment, schemes, and properly resizing partitions.

During the partitioning process, or when resizing partitions later, it is possible for errors to occur or for partitions to become corrupted. This can lead to data loss if backups are not available.[2] Having multiple partitions essentially splits up the drive, so there are more opportunities for potential issues compared to an unpartitioned drive.

There are also performance trade-offs to consider. A greater number of partitions requires more work from the OS to manage them. And frequent reads/writes across multiple partitions on the same physical drive can reduce performance compared to an unpartitioned drive.

Use Cases for Partitioning

There are a few common use cases for partitioning an external hard drive:

Dual Booting Operating Systems

Partitioning allows you to install multiple operating systems on the same drive and dual boot between them (for example, Windows 10 and Ubuntu Linux) (Source). Each OS would get its own partition.

Storing Backups

Creating a separate partition just for backups keeps that data protected and isolated. If the main partition fails, the backup partition and data will remain intact (Source).

Separating Personal and Work Data

Partitioning allows keeping personal files and work/business files completely separate by assigning them their own partitions (Source).

How to Partition a Drive

There are a few different ways to partition an external hard drive in Windows:

Using Disk Management

Disk Management is a built-in Windows tool that allows you to manage disk partitions. To use it:

  1. Open Disk Management (right-click the Start menu and select “Disk Management”).
  2. Right-click the external drive you want to partition and select “Shrink Volume”.
  3. Enter the amount you want to shrink the volume by.
  4. Right-click the unallocated space and select “New Simple Volume”.
  5. Follow the wizard to create your new partition.

Disk Management allows you to resize, create, delete, format, and change drive letters for partitions. It’s a simple way to partition drives in Windows (source).

Third Party Tools

There are many third party tools that offer more flexibility and options for partitioning compared to Disk Management. Popular options include:

  • MiniTool Partition Wizard – Free disk partitioning software with advanced features.
  • AOMEI Partition Assistant – Allows merging, splitting, formatting, and converting partitions.
  • EaseUS Partition Master – Can resize, move, merge, clone, and recover partitions.

Third party tools give you more control over how your drive is partitioned and allow you to perform more complex operations (source).

Command Line

The diskpart command can be used to partition drives from the Windows command prompt or a batch file. Key commands include:

  • list disk – Lists available disks.
  • select disk X – Selects a disk to partition.
  • clean – Removes any existing partitions.
  • create partition primary – Creates a primary partition.
  • format fs=ntfs quick – Formats the partition.

The command line allows scripting the partitioning process but requires more technical expertise (source).

Choosing Partition Schemes

When partitioning a drive on Mac, you have two main options for the partitioning scheme: Master Boot Record (MBR) and GUID Partition Table (GPT). MBR is an older standard that dates back to the early days of PCs, while GPT is newer and designed for modern systems and large hard drives.

With MBR, you are limited to 4 primary partitions per drive. To create more than 4 partitions, you need to make one of them an extended partition, which can contain logical partitions. GPT does not have this limitation and allows you to create many partitions.

GPT has a number of advantages over MBR. It supports larger partition sizes, stores more partition information making it more robust, and includes checksums to prevent data corruption. Apple recommends using GPT for drives over 2TB on Intel Macs.

Another consideration is cluster size. This determines the minimum allocation unit for files on the partition. A smaller cluster size reduces wasted space for small files, but requires more system resources to manage. For hard drives, a reasonable default is 4K (4096 bytes), but this can be customized if needed.

Partition Alignment

Proper partition alignment is important for optimal performance when working with hard drives and SSDs. When partitions are aligned with the underlying physical sectors of the storage device, it allows for faster read/writes and reduces unnecessary operations.

For traditional HDDs, misaligned partitions can cause additional seek operations as the drive head moves between mismatched logical block addresses (LBAs) and physical sectors. This results in slower performance. As explained by Paragon Software, “Our performance tests show that partition alignment boosts hard disk drive data transfer rate by up to 20%” (source).

The importance is even greater for SSDs, where misaligned partitions can significantly reduce read/write speeds and lifespan. Writes to an SSD occur in pages, typically 4KB in size. A misaligned partition may force the drive to read an entire page, update a small portion of it, and rewrite the entire page – increasing wear. With proper alignment, an entire page can be directly written. As Thomas-Krenn notes, alignment to erase block boundaries “increases the performance and the lifespan of SSDs” (source).

File System Options

When partitioning an external hard drive, you have several file system options to choose from. Three of the most common choices are NTFS, exFAT, and FAT32.

NTFS is the default system for Windows computers. It supports large partition sizes up to 256 TB and large files up to 16 TB. NTFS also offers security features like permissions and encryption. However, NTFS is proprietary to Windows and read-only on macOS without additional software. Overall, NTFS is a good option if you mainly use Windows.

exFAT is supported natively on both Windows and macOS. It removes some of NTFS’s advanced features but supports large partition sizes up to 128 PB and large files up to 16 EB. exFAT works well for external drives shared between Windows and macOS devices. However, exFAT lacks some security features and may be less stable compared to other options.

FAT32 is compatible with all major operating systems. However, it limits partitions to 32 GB and individual files to 4 GB. FAT32 works best for small USB flash drives shared between many devices. But for larger external hard drives, NTFS or exFAT are usually better choices.

When deciding the file system for an external drive, consider compatibility, partition sizes, security needs, and types of data stored. For a drive used just on Windows, NTFS is recommended. For cross-platform sharing, exFAT offers a good balance. And for small removable media, FAT32 remains a tried and true option.

Managing Partitions

One of the advantages of partitioning a drive is the ability to easily manage the partitions after setup. There are several key tasks for managing partitions:

Resizing Partitions

You may need to increase or decrease the size of a partition if your needs change over time. Most partitioning tools like MiniTool Partition Wizard and GParted allow you to easily resize partitions without losing data. This involves shifting data around to expand or shrink the partition size.

Deleting Partitions

Deleting a partition completely removes the partition and all data stored on it. This is useful if you no longer need a partition, but make sure to back up any important data first. Simply right-click on the partition you want to delete and select “Delete”.

Merging Partitions

If you have multiple partitions that you want to consolidate, you can merge them together. This combines two partitions into one larger partition while preserving all the data. Just be aware that merging partitions can be a complex operation.

Maintenance and Optimization

Over time, partitions can become fragmented which can degrade performance. Defragmenting partitions helps optimize them by rearranging data so files are stored sequentially. It’s also a good idea to occasionally error check partitions using built-in tools like CHKDSK in Windows.


In summary, there are both pros and cons to partitioning an external hard drive. The main benefits of partitioning include organizing files more efficiently, isolating sensitive data, having multiple operating systems on one drive, and the ability to easily format one partition while keeping other data intact. However, there are also some downsides such as reduced disk space, more difficult data recovery, and added complexity when partitioning.

Partitioning an external drive makes the most sense for power users who want to organize their data or run multiple operating systems on one drive. For casual users who just need extra storage space, a single partition is generally fine. However, if security is a concern and you want to isolate certain files, partitioning can help achieve that. Overall, it depends on your specific needs and technical comfort level. With the right understanding of the trade-offs involved, partitioning can be a useful tool for customizing external drives.