What Is Superfetch and How Can You Disable It?

Superfetch is a standard Windows feature that preloads the apps you use most frequently. By loading these programs in advance, Service Host Superfetch aims to speed up your PC . Superfetch is part of Windows 10, and has come built-in with all versions of Windows since Windows Vista in 2007.

Superfetch can extend startup times by preloading programs before Windows can get itself up and running. Though Superfetch is usually helpful, sometimes it can slow down your PC. As a background service, Superfetch constantly uses some CPU and RAM resources. Try disabling Superfetch if you encounter these issues.

How to disable Superfetch in Windows 10

You may notice that Superfetch is slowing down your PC, rather than speeding it up. If that’s the case, here’s how to turn off Superfetch in Windows 10, in two different ways:

Turn off Superfetch in Windows 10 with services.msc

1. Right-click the Windows button in the lower-left corner of your desktop, then click Run. Type services.msc and click OK to open the Windows Service Manager.

   

2. In the Windows Service Manager, locate the Sysmain entry. Double-click it and set the Startup type status to Disabled.

   

3. Click OK, then reboot your system. Service Host Superfetch will be disabled.

Turn off Superfetch with the Windows 10 Command Prompt

1. Open the Start menu and type cmd. Select Run as administrator. Click Yes when prompted.

   

2. Paste the following command into the Command Prompt, then press Enter:

   sc stop “SysMain” & sc config “SysMain” start=disabled

   

3. Restart your computer to use Windows with Superfetch turned off.

At times, Superfetch can eat up a lot of CPU resources and RAM, which may drive your disk usage up to 100%, raise CPU temperatures, and decrease your computer’s speed. If these problems persist even with Superfetch turned off, go ahead and turn it back on — your performance issues aren’t being caused by Superfetch.

How to enable Superfetch in Windows 10

Turning on Superfetch may help improve performance. Here’s how to turn on Superfetch in Windows 10:

Turn on Superfetch in Windows 10 with services.msc

1. Right-click the Windows button in the lower-left corner of your desktop, then click Run. Type services.msc and press Enter.

   

2. Scroll down and double-click Sysmain, then choose Automatic (Delayed Start).

   

3. Click OK, then restart your computer. Superfetch will now be enabled in Windows 10.

Turn on Superfetch with the Windows 10 Command Prompt

1. Type cmd in the Start menu, click Run as administrator, and choose Yes when prompted.

   

2. Enter the command below into the Command Prompt, then press the Enter key.

   sc config “SysMain” start=auto & sc start “SysMain”

   

3. Restart your computer to enable Superfetch.

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How does Service Host Superfetch work?

Service Host Superfetch predicts which programs you’ll use at which times, then preloads those apps into your RAM (short-term memory). Here’s a detailed look at how Service Host Superfetch works:

1. Superfetch preloads apps (and boot files) into your RAM when it thinks you’re going to use them. This is designed to prevent Windows from needing to dip into the slower hard disk as frequently as it otherwise would.

2. By analyzing your behavior, Superfetch’s algorithm will anticipate which apps you’ll use and when. Superfetch is able to predict up to three apps at any time.

3. Superfetch knows to prioritize active programs over background tasks, such as defragging your hard drive. Windows Service Host Superfetch will run these tasks when your computer is idle.

4. Superfetch learns as you continue to use your computer. As your habits change and you use different programs more or less frequently, Superfetch adapts to your needs.

How to monitor Superfetch’s disk usage

If your computer feels slower than it should be, you can check to see if Superfetch is causing high disk usage. Here’s how to monitor Superfetch in Windows 10:

1. Right-click the Taskbar and choose Task Manager.

2. In the Task Manager, find an item called Service Host: SysMain — also known as Service Host Superfetch.

   

Superfetch’s disk usage should be minimal at most — if you see a high CPU usage percentage or double-digit MB/s disk usage for more than a few minutes, turn Superfetch off. Should this persist, you may note high CPU temperatures as a result.

Should I disable Superfetch?

You should disable Superfetch if you notice that it’s increasing CPU usage, eating up RAM, or throwing your hard disk into overdrive. With Superfetch overusing disk resources, it could cause a noticeable drop in your computer’s speed and performance. This can happen even if you’re using an SSD instead of an older HDD.

Slowdowns caused by Superfetch typically result from Superfetch preloading too many apps, or guessing wrong and loading apps that you aren’t going to use. When you choose to open a different program, your RAM isn’t ready for it. Turn off Superfetch and see if your SSD or HDD works any faster. Learn more about how to check your RAM.

Why do we need Superfetch in Windows 10?

Most of the time, Superfetch improves the performance of Windows PCs. The more Superfetch learns about your habits, the more accurately it can predict when you’ll use a certain app and preload it.

When you install new apps, the Superfetch queue is cleared to ensure there’s enough RAM. As you use these new apps, Superfetch analyzes when and how often. Microsoft’s Michael Fortin has spoken at length about the Superfetch design process and how it can improve your PC’s performance.

But sometimes, Superfetch can actually cause more problems than it fixes, and turning off Superfetch may help.

Is Service Host Superfetch necessary for gaming?

By preloading your game when you’re about to play, Superfetch should help optimize your PC for gaming. But some gamers report Superfetch taking up disk resources — even after a gaming session is over.

Game files can be very large, sometimes exceeding 100 GB. If Superfetch detects that you regularly play a game, it may get a bit too excited and attempt to preload the game’s files into your RAM — this is where things can go wrong. Superfetch will struggle to deal with these massive file sizes, and you may want to disable Superfetch to see if performance improves.

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