Turning disk write caching on may increase operating system performance.
Modern PCs are designed to balance speed, stability, and data safety, but improving one area often comes with tradeoffs. Storage performance plays a major role in how responsive a system feels, especially when opening applications, saving files, or transferring large amounts of data. To improve performance, operating systems rely on various optimization techniques that manage how and when data is written to storage.
What Is Disk Write Caching?
One of these techniques is Disk Write Caching, which allows your computer to temporarily hold data in memory before writing it to the hard drive. In practical terms, this can improve application responsiveness and speed up file transfers by reducing the number of direct write operations. However, because data isn’t written to disk immediately, this approach can also introduce risks under certain conditions, such as unexpected power loss.
Understanding how write caching works — and when it makes sense to use it — can help you make better decisions about your system’s performance and data protection. In the sections below, we’ll explain how this feature works, its benefits and drawbacks, and what you should consider before enabling or disabling it.
How Does Disk Write Caching Work?
Disk Write Caching allows programs on your computer to handle files without having to wait for all the data to be written to the hard disk. If that sounds a bit unclear, here’s an example of this feature in practice.
Imagine that you are using a video editing tool to edit a 30-minute-long video you filmed during the weekend with your family. It’s a high-quality H.264 720p video file, so the whole video weighs around 10GB. After editing it, you break it down into three smaller videos, each of which ends up weighing around 3GB. You save these in your video collection, alongside your other family videos.
With Disk Write Caching enabled, your operating system makes a note of these files and stores this information in your OS’s memory. But it doesn’t actually save the files themselves, not right away.
This is true not only for the files you save manually but also for any other files the application may modify on the hard disk. Later on, Windows will automatically write the information to the hard disk in the background, and then remove the information about the files stored in the cache.
This means that your application and OS as a whole will not be taxed by the file-writing process, which often has a significant impact on your computer’s performance.
The Downside
On most systems, Disk Write Caching improves performance notably for most file operations. But there’s a catch to this. As noted above, this type of caching doesn’t save the information right away.
So, what if your system crashes or there’s a power outage before the data gets written to the disk? What happens to the data then?
No surprise here: the data gets lost or corrupted. This could mean both the actual files you saved as well as application-specific data.
But how long is the delay between data caching and the actual writing of the data on the disk? This may depend on your operating system and hard disk drive. We don’t have clear numbers on this one, but Windows seems to be flushing its internal file write cache every eight seconds, while the actual writing of data may take even longer.
In computer times, that’s quite a lot, and so with Disk Write Caching on, the risk of losing data is always there.
When it’s just files that are being copied from one location to another, the lost data can often be recovered by copying it again from the source. But for data that’s being moved, or that’s being copied from an external source or over a network, the loss can be irreversible.
Still, for many users, the performance benefits of Disk Write Caching far outweigh the risks.
How to Enable Disk Write Caching
Disk write caching is available on Windows 7, 8, and 10 and other operating systems. Follow these steps to Enable it.
- Press the Windows button to bring up the search tab.
- Type Device Manager and press Enter.
- Find Disk Drives in the list.
- Right click on the disk for which you want to Enable Write Caching and click on Properties.
- Go to Policies.
- Enable write caching on the device.
- Restart your computer for the change to take effect.
One way to take advantage of Disk Write Caching and mitigate the data loss risks it entails is to get a backup power supply. In this way, if your power fails, the power supply should give your operating system enough time to write all the data on the disk.
Also important is to avoid turning your computer off instantly by pressing down the power button. Even if the screen freezes, your OS may still be able to write the data to the hard disk in the background.
Last but not least, don’t unplug your laptop from the outlet if the battery’s dead, and don’t remove the battery without first shutting down the computer.
Weighing Performance Gains Against Data Safety
Disk Write Caching can noticeably improve application responsiveness and file transfer speeds, but it comes with tradeoffs. Because data isn’t written to disk immediately, unexpected shutdowns or system crashes can result in lost or corrupted files. Laptops are generally less exposed to this risk thanks to built-in batteries, while desktop systems without a backup power source are more vulnerable.
That doesn’t mean write caching is a bad choice. For systems where performance matters more than absolute data safety — and where regular backups are in place — enabling it may be worthwhile. The key is understanding how your PC is used and deciding whether the potential performance gains justify the added risk. Making an informed choice helps you get the most out of your system without unpleasant surprises.