What Size of Disk Partition is Needed for Windows 11?

Last month, I reinstalled the Windows operating system. With the need to install significantly more software than before, I began to pay attention to the space usage of the system partition.

Why Care About System Partition Space Usage

Professional users may need to pay attention to the space usage of the system partition for the following reasons:

• Disk capacity to purchase
  I use a dedicated hard drive to install the operating system. Clearly, the actual usage of the system partition determines how large a hard drive I need to buy. Considering cost-effectiveness, the hard drive capacity doesn't need to be too large, as long as it meets normal usage needs.

• Disk space to allocate
  If the system partition shares the same hard drive with other data partitions, then it’s necessary to consider how much space to allocate for the system partition. Of course, there are tools available to resize partitions later on, but moving data always carries some risks, and the preparation work can be cumbersome. Improper operations could lead to data loss.

• Disk performance and lifespan
  For a working hard drive, the partition should have some free space. When space usage exceeds 80%, the file system is prone to fragmentation, affecting read and write performance. If the system partition is too full, operations that require writing to the disk, such as temporary files, virtual memory, system updates, and logs, will be impacted, leading to degraded system and software performance or failures in normal operation. In the case of a solid-state drive (SSD), high space usage can shorten its lifespan and affect read/write speeds.

Microsoft states that Windows 11 requires at least 64 GB of disk space. However, this is only the installation requirement; many users' actual usage far exceeds this. There aren’t many useful references online regarding the actual disk usage of Win11, so I’d like to share my experience here.

First, it's important to note that the actual usage of the system partition varies based on hardware models, operating system versions, software installation locations, daily usage habits, and more—everyone's situation is different.

Basic Computer Information

• Operating System: Windows 11 23H2, Professional Edition
• Memory: 16 GB
• System Partition Size: 200 GB

Disk Space Usage Overview

When Windows 11 was freshly installed and before any drivers were added, the initial usage of the system partition was about 28 GB.

Currently, the system is running very stable. The software I use is listed in the next section, and many are related to creative design and program development. Currently, the usage of the system partition is about 115 GB, with some fluctuations.

Considering future software installations and the need to reserve free space, it can be inferred that users like me need to prepare 200 GB of space for the system partition.

Software in Use

Typically, I allow software to be installed on the system partition. Here are the main software applications:

• Document Processing:
  Microsoft Office (Word, Excel, PowerPoint, OneNote), Project, Adobe Acrobat

• Note-taking:
  Logseq, Xmind

• Graphics:
  NVIDIA GeForce Experience

• Program Development:
  Visual Studio Code, Sublime Text, Git, Python, Node.js, VMware Workstation

• Creative Design:
  Adobe Creative Cloud, After Effects, Audition, Bridge, Illustrator, Lightroom, Media Encoder, Photoshop, Premiere Pro, Cinema 4D, CapCut, Figma, Billfish, FontBase

• Multimedia & Entertainment:
  PotPlayer, Steam, OBS, Netease CloudMusic

• Web Applications:
  Google Chrome, Baidu NetDisk, WeChat, Thunder

These applications tend to take up more space. Additionally, there are some smaller applications not listed.

I keep the software updated to the latest versions, as this helps with security and performance.

Disk Space Used by Software

Here are the application sizes I found on my machine, for rough reference:

Optimizing Disk Space Usage in the Operating System

Some system features and usage habits may affect the space usage of the system partition.

Temporary Files

In the system settings, you can view and clear certain system-level temporary files. Go to System -> Storage -> Temporary Files, where you can see various entries, select them, and click delete to free up disk space.

Hibernation

Hibernation is a power management mode in Windows that saves the current system state to the hard drive and completely powers off the computer. When the computer restarts, it resumes from the state it was in before hibernation. Unlike sleep mode, hibernation fully shuts off power, so it doesn’t consume electricity.

Hibernation writes everything in memory (including open programs and unsaved work) to a file called hiberfil.sys on the hard drive. This hibernation file is located in the root directory of the system partition. Depending on memory usage, this file can reach several GB.

You can configure the hibernation feature by running the following command as an administrator.

• To disable hibernation:

powercfg -h off

• To enable hibernation:

powercfg -h on

Virtual Memory

Virtual memory uses hard drive space to simulate physical memory, preventing the computer from stalling when running programs due to insufficient memory. When physical memory is nearly full, the system moves temporarily unneeded data from memory to a special file on the hard drive called the paging file. This frees up physical memory for higher priority tasks.

By default, the virtual memory paging file pagefile.sys is located in the root directory of the system partition, and its size is controlled automatically by the system. You can modify system settings to adjust the paging file size; this article mentions how to do that. Manual adjustments may lead to software errors, so caution is advised.

System Restore (System Protection)

The System Restore feature allows you to save the system configuration at a specific point in time as a snapshot. If you encounter serious issues after installing system updates, drivers, or applications, or if the system configuration is modified, this feature can restore the system to a previously created snapshot to help fix the problem.

In Windows 11, the System Restore feature is enabled by default. You can access it by searching for Advanced System Settings in the Start menu, then clicking on the System Protection tab and selecting Configure to view its settings. By default, my system uses 5% of the disk space to store restore points. Users can enable or disable the System Restore feature, or adjust the maximum disk space usage based on their needs.

Personal Files

In addition to user-defined partitions for personal files, Windows treats the %USERPROFILE% directory as a storage location for personal files. For instance, if the username is John, the system creates a personal folder at C:\Users\John, which contains folders like Desktop, Documents, Pictures, etc., for users to organize their files.

Many applications store configuration and data files in the personal folder. For example, WeChat saves login account information, chat logs, downloaded files, etc., in %USERPROFILE%\Documents\WeChat Files. By default, these files can take up a significant amount of space in the system partition.

A convenient method is to move such personal files to another partition. For example, by right-clicking the C:\Users\John\Documents folder, selecting Properties, and changing the storage location in the Location tab, you can redirect it to another partition, thus freeing up space in the system partition. This approach has the added benefit that if you need to reinstall the system and format the system partition, folders moved to other partitions will not be affected, allowing for a quick recovery of software configurations after the system installation.

Font Files

Designers often use many fonts. If numerous fonts are directly installed into the system, such as in the %WINDIR%\Fonts folder, it can take up a lot of space in the system partition.

Some software can easily manage fonts and only load them into design software when needed. For instance, I use FontBase for this purpose. This way, you don’t need to install a large number of fonts into the system, but can manage them separately with other design materials. You can also search for "font management software" to find a suitable tool.

Game Files

Some games have large file sizes. I install games on other hard drives, so they don’t occupy space on the operating system's hard drive.

Dynamic Changes in Disk Usage

I also observed that the usage of the system partition can fluctuate dynamically, sometimes significantly. One day, I noticed that the used space gradually increased to 125 GB, then dropped to 105 GB the next day. Without a detailed analysis, I am unsure of the reasons behind this phenomenon. However, it seems to suggest that ample available disk space should be reserved to accommodate the system’s special requirements.