Windows 10 is a definite improvement over previous versions in many ways—but it can also feel slow and sluggish when it isn’t configured properly. Of the many ways to improve Windows 10 performance, there’s one lesser-known feature that you should know about: Superfetch.
In this article, you’ll learn everything you need to know about what Superfetch is, how it works, why it might be problematic, and how to disable it if it’s causing issues.
What Is Superfetch?
Superfetch is a feature that was introduced back in Windows Vista. The official description of the Superfetch service says that it “maintains and improves system performance over time,” but that’s vague and doesn’t explain the whole story.
Superfetch shows up as “Service Host: Superfetch” in the Windows Task Manager. It sits quietly in the background, constantly analyzing RAM usage patterns and learning what kinds of apps you run most often. Over time, Superfetch marks these apps as “frequently used” and preloads them into RAM ahead of time.
The idea is that when you do want to run the app, it will launch much faster because it’s already preloaded in memory.
By default, Superfetch is designed to take up all your available RAM space with preloaded apps. Don’t worry: it only deals with unused memory. As soon as your system needs more RAM (e.g. to load an app that wasn’t preloaded), it relinquishes the needed memory as necessary.
Note that Superfetch is not the same thing as Prefetch, which is the preloading memory manager that was introduced back in Windows XP. Superfetch is actually the successor to Prefetch. What’s the difference? Prefetch did not analyze usage patterns over time and adjust its preloading parameters accordingly.
Is Superfetch Really Necessary?
For the most part, Superfetch is useful. If you have a modern PC with average specs or better, Superfetch most likely runs so smoothly that you won’t ever notice it. There’s a good chance Superfetch is already running on your system right now and you didn’t even know.
But there are some “problems” that can arise with Superfetch:
- Since Superfetch is always running in the background, the Superfetch service itself is always using some CPU and RAM.
- Superfetch doesn’t eliminate the need to load apps into RAM. Rather, it relocates the loading to an earlier time. Whenever that loading happens, your system still experiences the same slowdown as if you were launching the app without Superfetch.
- System startup can be sluggish because Superfetch is preloading a bunch of data from your HDD to RAM. If your HDD runs at 100% for a few minutes every time you start or restart your computer, Superfetch could be the culprit.
- The performance gains of Superfetch may be unnoticeable when Windows 10 is installed on an SSD. Since SSDs are so fast, you don’t really need preloading. If this interests you, check out our guide to moving Windows from HDD to SSD.
Superfetch has also been known to cause performance issues while gaming, particularly on systems that have 4GB of RAM or less. It’s unclear why this happens because it doesn’t occur for everybody, but we suspect it has to do with RAM-heavy games that constantly request and free up memory, which may cause Superfetch to constantly load and unload data.
Is it safe to disable Superfetch? Yes! There is no risk of side effects if you decide to turn it off. Our recommendation is that if your system is running well, leave it on. If you have issues with high HDD usage, high RAM usage, or degraded performance during RAM-heavy activities, then try turning it off and see if it helps. If it does, keep it off. Otherwise, turn it back on.
Note: To boost performance on a RAM-sparse system, we recommend tweaking the Windows virtual memory limit and tweaking Windows visual effects. You can also try these tips for faster startup and shutdown.
How to Disable Superfetch on Windows 10
To reiterate, we don’t recommend disabling Superfetch except as a troubleshooting measure for the potential issues mentioned above. Most users should keep Superfetch enabled because it does help with overall performance. If you aren’t sure, try turning it off. If you don’t notice any improvements, turn it back on.
Using the Services App
Step 1: Launch the Services app. Open the Start Menu, search for services, then launch the Services app. Alternatively, open the Run prompt by pressing Windows key + R, then type services.msc and click OK.
Step 2: Disable the Superfetch service. Scroll down until you see Superfetch, right-click on it, and click Stop. Superfetch is now disabled.
Step 3: Prevent Superfetch from running automatically. Still in the Services app, right-click on Superfetch and select Properties. Under the General tab, look for Startup type and change it to Disabled. (Or Manual if you’d like the option to turn it on when you need it.)
Using the Registry Editor
The Services app is the preferred method for this, but if it doesn’t work for some reason, you can always edit the registry key directly. Before you do this, make sure you back up the registry in case something goes wrong (it’s more common than you think).
Step 1: Open the Registry Editor. Open the Start Menu, search for regedit, then select it from the results. Alternatively, open the Run prompt by pressing Windows key + R, then type regedit and click OK.
Step 2: Find the Superfetch key. Using the left sidebar, navigate to the following:
HKEY_LOCAL_MACHINE / SYSTEM / CurrentControlSet / Control / Session Manager / MemoryManagement / PrefetchParameters
Step 3: Disable Superfetch. In the right panel, you should see a key called EnableSuperfetch. Right-click on it and select Modify… to bring up the key editor. To disable Superfetch, change Value Data to 0 and click OK.