Virtual memory: Everything you need to know

Computers depend on various elements for optimal functionality. To enable data access and user interaction, they rely on several components, with virtual memory being one of them. Virtual memory plays a key role in ensuring seamless performance and efficient handling of daily operations.  

Yet, understanding virtual memory can be a challenge, especially when distinguishing it from the physical memory found within our computers. So, what exactly is virtual memory? How does it differ from physical memory? And how can you increase your virtual memory? We’ll answer these questions below. 

Virtual memory, or virtual storage, is a memory management technique employed by computer systems to optimize the utilization of physical storage. In simple terms, when the computer is low on physical memory – the RAM chips you plug in to your computer – it temporarily uses space on the hard drive or solid state drive to store and swap information back and forth from the physical RAM as needed, in order to keep the computer working as efficiently as possible.   

Without virtual memory, the computer would be unable to keep working when it filled the available RAM.  

Virtual memory management was helpful when SSDs were expensive, because this could reduce costs, or when spinning hard disks were being used for storage, because these were extremely slow compared to RAM. Now that there are lots of options (price points) for SSDs, the need for virtual memory has naturally reduced.

The size of the paging file, a key component of virtual memory, primarily depends on the operating system, which controls how and when the paging file is used, and the available disk space, which may limit the maximum size of the page file.  

For instance, if a computer has 8GB of physical RAM, the computer might create a paging file of 2GB to handle the excess memory requirements. Typically, the paging file is managed by the operating system. It is possible to manually change the virtual memory settings on your computer, but you should be careful. If you are not careful, you may end up harming overall system performance.  

While it enables programs to continue functioning by supplying additional "fake" RAM, the vastly slower access and performance of HDD and SSD compared to actual RAM can result in noticeable performance degradation when heavily relying on virtual memory. 

Physical memory consists of chips that are purchased and installed in the DIMM slot on the motherboard, aiming for fast and high-speed operations. In comparison, virtual memory becomes necessary when physical memory or RAM, which is the primary memory utilized by a computer from the outset, is fully occupied.  

When it comes to speed, virtual memory is significantly slower than physical memory as it relies on hard disk drives or solid-state drives. These can be thousands of times slower than physical RAM chips. On the other hand, physical memory is designed to be fast, ensuring higher-speed operations for efficient computing. The limitations of physical memory are dictated by the size of the chips present on a memory module.  

To increase the size of virtual memory, you can manually allocate more hard drive space - we’ll discuss this in more detail later in this article. This is in stark contrast to physical memory, which is confined to the size of the chips present on a memory module. While adding more virtual memory may help improve system performance, the best thing you can do if you are low on RAM is to upgrade your computer memory. Conversely, increasing physical memory can have a tangible impact on a computer's performance, leading to enhanced efficiency and responsiveness.  

Virtual memory organizes information on the hard drive in the form of pages, hence the term "paging file" referring to the size and name of these pages. In contrast, physical memory stores data within RAM chips and clears them once the operation is completed, such as when closing a document.  

We have already discussed the speed difference between physical RAM and virtual memory. This is especially true if you are still using a hard drive with spinning platters. You can significantly improve your system performance by upgrading to a solid state drive. 

Virtual memory used to require more user-maintenance in older versions of Windows, but modern operating systems like Windows 10 or Windows 11 can manage this more effectively.  

Frequent use of virtual memory is a sign your workload requires more RAM, and that your computer would benefit from any options for memory upgrades our System Scanner or Upgrade Selector identify for your system.  

Remember that it is generally recommended to let the operating system automatically determine the appropriate paging file size. This is because, as you use your computer, the paging file dynamically adjusts over time. When your computer's memory is pushed to its limits, the operating system automatically increases the virtual memory size.  

Managing virtual memory in a Windows® system is relatively easy, but largely unnecessary. Windows will, by default, adjust virtual memory on the fly based on your needs and your installed RAM.  

Windows tries to set itself to what it expects you to need based on your installed RAM and it will adjust itself if your usage spikes. This can lead to it self-adjusting to end up taking a large amount of space if you are currently running a large amount of RAM (for example a system with 8GB of RAM will often default to 8GB of virtual memory and can grow as large as 16GB).   

Manual adjustments to this setting are done at your own risk, and this should not be attempted unless you have solid guidelines about what you actually need. Under-allocating space for virtual memory can lead to programs or your system as a whole malfunctioning. Additionally, older programs are designed with the assumption there is a page file in place for them to use, and malfunctions of individual programs can occur if adequate virtual memory is unavailable to them due to incorrect configuration. 

Step 1: Right-click on Start (or hold the Windows key and press X) and select System. This defaults to the About tab.  
Step 2: Select Advanced System Settings.  
Step 3: Click the Settings button under Performance to open a Performance Options window.  
Step 4: Select the Advanced tab here.  
Step 5: The Virtual Memory field will show the current page file size.  
Step 6: Click Change to open a Virtual Memory window, allowing you to disable automatic allocation and modify the allocated space. 

If you are still running Microsoft’s older operating system, virtual memory will be more useful, but the steps to configure this in Windows XP will be different. You should also consider upgrading your computer to ensure you can benefit from the latest features and important security updates.  

Step 1: Head to System settings  
Step 2: Go to About  
Step 3: Under Device specifications, find and click Advanced System Settings  
Step 4: Click on Settings under the Performance banner  
Step 5: Head to Advanced tab, and click on Change under Virtual memory  
Step 6: Uncheck Automatically manage paging file size for all drives. 
Step 7: Click the Custom size and set the Initial Size to 1.5x, and the Maximum to 4x the size of your RAM  
Step 8: Click OK  

Virtual memory management has historically been useful in older, slower systems with less advanced operating systems. Today, there is less need for users to get involved in the details of file management.  

There are many benefits to adding extra RAM to your system. If you need affordable storage, consider performance NVMs SSDs for heavy workloads and lower price options like SATA SSDs for big storage.  

Make sure you use our System Scanner to check your new components are fully compatible with your computer.