Enable or Disable SysMain & Prefetch for SSD in Windows 11/10 (2023)

In this article, we will see how Windows 11/10/8/7 treats Prefetch and SysMain on Solid-State Drives. Yesterday we saw how Windows treats Defragmentation on Solid-State Drives. Before we start, let me make it clear that it t is not a good idea to disable SysMain (Earlier called SuperFetch) or Prefetch as it may degrade system performance. Leaving these services to their default settings is best.

SysMain (Superfetch), Prefetch & SSD in Windows 11/10

Every time you run an application in your PC, a Prefetch file that contains information about the files loaded by the application is created by the Windows operating system. The information in the Prefetch file is used for optimizing the loading time of the application the next time that you run it.SysMain attempts to predict which applications you will launch next and preloads all of the necessary data into memory. Its prediction algorithm is superior and can predict which next 3 applications you will launch by what time in a day.

In short, SysMain and Prefetch are Windows Storage Management technologies that provide fast access to data on traditional hard drives. On Solid State Drives, they result in unnecessary write operations.

(Video) How to Disable Superfetch/SysMain In Windows 11 [Tutorial]

How to Disable SysMain in Windows 11/10

The SysMain service is the one that is related to Superfetch. Its job is to maintain and improve system performance over time. It is found in the System32 folder. The Services is the same, but the Display name for it has been changed in Windows 10 from Superfetch to SysMain. Should one for some reason need to manually disable them, this is how one can disable SysMain.

To disable SysMain in Windows 11/10, follow these steps:

  1. Press Win+R to open the Run prompt.
  2. Type msc and press the Enter button.
  3. Double-click on the SysMainservice.
  4. Select Disabled from the Startup type drop-down list.
  5. Click the OKbutton.

Run services.mscto open the Services Manager. Scroll down to SysMain (Superfetch) service, which is responsible for maintaining and improving the system performance over time.

Double-click on it to open its Properties box. Click on Stop to stop the process. Make the startup type Disabled and click on Apply.

Enable or Disable SysMain & Prefetch for SSD in Windows 11/10 (1)

(Video) Windows 10 Disable And Enable Prefetch And Superfetch - Increase Your SSD Lifespan

You will have to restart your computer for the system changes to take effect.

How to Disable Prefetch in Windows 11/10

To disable Prefetch in Windows 11/10, follow these steps:

  1. Press Win+R to open the Run prompt.
  2. Type regedit > press the Enterbutton.
  3. Click the Yes
  4. Go to PrefetchParameters in HKLM.
  5. Double-click on the EnablePrefetcher REG_DWORD value.
  6. Set the Value data as 0.
  7. Click the OKbutton.

To disable Prefetch in Windows, Run regedit to open the Registry Editor. Navigate to the following registry key:

HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\PrefetchParameters

Enable or Disable SysMain & Prefetch for SSD in Windows 11/10 (2)

Double-click on EnablePrefetcher on the right side to open its DWORD value box.

(Video) Fix 100% CPU/Disk Usage: Superfetch/SysMain | Windows 10 Guide

The possible values for EnablePrefetcher are:

  • 0 – Disable Prefetcher
  • 1 – Application launch Prefetching enabled
  • 2 – Boot Prefetching enabled
  • 3 – Application launch and Boot Prefetching enabled

The default value is 3. To disable Prefetch, set it to 0. Click OK and Exit.

Incidentally, you can also disable or tweak the Suoerfetcher here – you will see the EnableSuperfetcherDWORD just below it.

The possible values for EnableSuperfetch are:

  • 0 – Disable SysMain
  • 1 – Enable SysMain for boot files only
  • 2 – Enable SysMain for applications only
  • 3 – Enable SysMain for both boot files and applications

If you are a Solid State Drive user, you may want to check out freeware SSD Lifethat can check the health of your Solid State Drive and SSD Tweakerwhich will help you tweak your Solid State Drives.

(Video) Disable Windows 11 Services You Don't Need

Does disabling Superfetch increase performance?

Although it doesn’t consume much storage, a malfunction can cause Superfetch or SysMain service high CPU usage. In such a situation, you could disable this service to increase the performance. However, in other cases, you might not find any improvement in performance after disabling this service.

Is it okay to disable Superfetch?

Yes and no. Yes, when you are getting problems due to this service. No, when you need this functionality. It is an in-built service of the Windows operating system, and it is required to make your PC smoother. That is why it is not recommended to disable Superfetch until it causes any issue.

Hope it worked!

Enable or Disable SysMain & Prefetch for SSD in Windows 11/10 (3)


Anand Khanse is the Admin of TheWindowsClub.com, a 10-year Microsoft MVP (2006-16) & a Windows Insider MVP (2016-2022). Please read the entire post & the comments first, create a System Restore Point before making any changes to your system & be careful about any 3rd-party offers while installing freeware.


Should I disable SysMain with SSD? ›

In Microsoft Windows 8 and newer, Superfetch functions differently than in previous versions of Windows and should not be disabled for the SSD.

Should I disable SysMain on Windows 11? ›

While it should be fine to keep SysMain enabled, you might want to disable it and see if you're experiencing sluggishness on your PC. Disabling it can improve speeds and boot time.

Should I turn Prefetch on or off SSD? ›

It is stated by Microsoft that SuperFetch and PreFetch should be disabled, if the OS is installed on a ssd, according to article http://support.microsoft.com/kb/2727880. But SuperFetch is used for loading data parts of applications, which have been used very often, to RAM.

Is it better to disable SysMain? ›

Answer: Sysmain is not a mandated program and disabling it won't turn out to be a BSoD error. But it is a beneficial service, so it is advisable to keep the service running.

What should I disable on my SSD Windows 10? ›

8 Useful Methods to Optimize SSD Windows 10/11
  1. Method 1: Disable Startup Programs. ...
  2. Method 2: Disable Fast Startup. ...
  3. Method 3: Confirm TRIM Is Enabled. ...
  4. Method 4: Make Sure the SSD Firmware Is Up to Date. ...
  5. Method 5: Enable Advanced Host Controller Interface (AHCI) Mode. ...
  6. Method 6: Turn on Write Caching.
May 13, 2022

Should I use SuperFetch with SSD? ›

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.

What should I disable in Windows 11 for better performance? ›

Speed Up Windows 11 with These Easy Steps (2022)
  1. Restart, Update.
  2. Disable Startup Programs/Apps.
  3. Debloat Windows 11.
  4. Change Power Mode.
  5. Defragment Hard Disk.
  6. Add More Memory on Windows 11 (RAM/SSD Upgrade)
  7. Disable Restartable Apps.
  8. Uninstall Unwanted Software/Bloatware.
Feb 1, 2023

Does turning off SysMain increase performance? ›

While keeping SysMain enabled should be acceptable, you might want to turn it off to determine whether your PC is running slowly. Speeds and boot times can be increased by disabling it.

What settings should I disable in Windows 11? ›

7 Things to Disable in Windows 11 for Better Gaming Performance
  1. Memory Integrity. ...
  2. SuperFetch. ...
  3. Virtual Machine Platform. ...
  4. PreFetch. ...
  5. Superfluous Background Apps and Services. ...
  6. Nagle's Algorithm. ...
  7. Mouse Acceleration.
Oct 25, 2022

Does Prefetch improve performance? ›

While prefetching resources does use additional bandwidth, it can improve most performance metrics. Time to First Byte (TTFB) will often be much lower, as the document request results in a cache hit.

Does Prefetch increase performance? ›

Runtime cache prefetching shows better performance. On an Itanium 2 based Linux workstation, it can increase performance by more than 20% over static prefetching on some benchmarks. For benchmarks that do not benefit from prefetching, the runtime optimization system adds only 1%- 2% overhead.

Does SSD cache improve performance? ›

The objective of SSD write caching is to temporarily store data until slower persistent storage media has adequate resources to complete the write operation. The SSD write cache can boost overall system performance.

Should I disable SysMain on SSD Reddit? ›

PSA: Be sure to disable the SuperFetch service ("SysMain") on upgrade. Microsoft re-enables it if you had it disabled. SuperFetch (aka SysMain).... that piece of crap service that constantly reads your HDDs/SSDs and decides for you what fills up your RAM.

Should I disable prefetch? ›

Contrary to many blog posts, disabling Prefetch and SuperFetch for SSD drives is actually unnecessary. It IS true that Prefetch and SuperFetch won´t provide a huge advantage for starting applications from SSD drives, as they are fast anyway. In this respect one could actually switch off the service.

Does SysMain cause lag? ›

SysMain service can cause computers to run slowly because they use system resources like CPU cores, Disk space, and memory.

Should I optimize my SSD Windows 11? ›

So, you need to check and optimize SSD performance in Windows 11 to get the best end-user experience. Most users install Windows in C Drive and use it for their storage too. However, you should use other Drives for saving your data and keep the Windows in a separate Drive for the best experience.

How do I optimize my SSD for faster performance? ›

How to Optimize SSD for Faster Performance (Windows Tweaks)
  1. IDE vs AHCI Mode. ...
  2. Confirm TRIM is Running. ...
  3. Avoid and Disable Disk Defragmenter. ...
  4. Disable Indexing Service/Windows Search. ...
  5. Enable Write Caching for SSDs. ...
  6. Update Drivers and Firmware for Your SSD. ...
  7. Optimize or Disable Page File for SSDs. ...
  8. Turn Off System Restore.

How do I optimize my SSD? ›

Before you start
  1. Choose the right formatting: GPT disk partition. ...
  2. Leave some free space on your SSD. ...
  3. Two is better than one. ...
  4. Set optimize schedules. ...
  5. Disable indexing. ...
  6. Set power mode for performance. ...
  7. Enable write caching. ...
  8. Disable low-power states for PCIe lanes.
Jun 20, 2022

What should I not do to my SSD? ›

SSD Dos & Don'ts
  1. Don't Defragment Your SSD. Unlike magnetic drives, fragmentation isn't going to hurt your SSD's speed. ...
  2. Do Check That Auto-Defrag is Disabled. Defragging your SSD is not only unnecessary, but it could shorten the life of your SSD. ...
  3. Don't Use for Archived Files. ...
  4. Do Enable TRIM. ...
  5. Don't Use Old Operating Systems.
Mar 16, 2015

Can SSD lose performance? ›

If your device includes a Solid-State Drive (SSD), you probably notice that the performance slows down dramatically as it fills up. You'll see this when opening apps and copying files will take longer than usual, and sometimes this will also cause freezing issues making your device harder to use.

What is the biggest drawback to SSD? ›

Price: The biggest disadvantage of a solid state drive is the cost. SSD costs more than a conventional hard disk drive. Recovery of Lost Data: The inability to recover old data is one of the biggest disadvantages of a SSD. Data is permanently and completely deleted from the drives.

How can I speed up my SSD Windows 11? ›

Optimize Your SSD on a Schedule
  1. Search for “Defrag” and click Defragment and Optimize. (Image credit: Tom's Hardware)
  2. Click the Change settings button. (Image credit: Tom's Hardware)
  3. Set how often you want Windows 11 to optimize your SSD.
Feb 19, 2023

How do I optimize Windows 11 for maximum performance? ›

How to speed up Windows 11
  1. Tip 1: Manage autostart programs.
  2. Tip 2: Clear memory via disk cleanup.
  3. Tip 3: Uninstall obsolete programs.
  4. Tip 4: Turn off visual effects.
  5. Tip 5: Turn off background apps.
  6. Tip 6: Turn off app notifications.
  7. Tip 7: Update Windows.
  8. Tip 8: Defragmentation.
Jan 5, 2023

What will happen if I end task SysMain? ›

It analyzes your computer usage patterns and optimizes app launching and programs on your computer. If you end this tasks this process will stop and there may not be any noticeable difference for your performance.In many of the cases it lags the performance by causing high disk usage.

How do I turn off SysMain in Windows 11? ›

Locate the SysMain entry here, right-click on it, and select Properties from the context menu. Alternatively, you can double-click on the service. Now, click on the Startup type dropdown menu, and select Disabled from the list of options.

Why is my PC disk always at 100? ›

Running lots of applications at once may cause 100% disk usage in Windows 10. Uninstalling these programs often isn't possible, because you may need them. Manually pausing the background apps is only a short-term solution, as many will restart upon bootup or run quietly in the background.

Should I enable memory integrity in Windows 11? ›

By turning on the Memory integrity setting, you can help prevent malicious code from accessing high-security processes in the event of an attack.

What features do you lose with Windows 11? ›

The following parts of the Windows shell are no longer available in Windows 11.
  • Lock Screen's quick status.
  • Tablet mode.
  • The Timeline feature in Task View.
  • The Save Search option in File Explorer.

Is it better to stay in Windows 10 or 11? ›

Windows 11 is worth the update for most people. It comes with a wide range of new features, performance improvements, and design changes. As the latest Windows OS, it usually gets more attention than Windows 10, too. There's not too much risk in upgrading to Windows 11, either.

What are the disadvantages of prefetching? ›

Prefetching suffers from certain disadvantages such as an increase in memory traffic, an increase in the number of executed instructions, and an increase in mem- ory requirement for some cases.

Should hardware prefetcher be on or off? ›

Hardware Prefetcher:

This default setting is "Enabled". In some cases, setting this option to Disabled may improve performance. Users should only disable this option after performing application benchmarking to verify improved performance in their environment.

What is prefetch Windows 11? ›

Since Windows XP, Windows creates a prefetch file every time you run an app for the first time. This file contains data the OS needs to speed up the app's load time whenever you run it. And this is a big help during the startup process since it helps Windows load faster.

What are the advantages of prefetching? ›

Hardware-based prefetching schemes have two main advantages over software-based schemes: (1) they have better dynamic information, and therefore can recognize things such as unexpected cache conflicts that are difficult to predict in the compiler, and (2) they do not add any instruction overhead to issue prefetches.

What are the advantages of software prefetching? ›

One main advantage of software prefetching is that it reduces the number of compulsory cache misses. The following example shows how a prefetch instruction would be added into code to improve cache performance. - which means that we prefetch 7 elements ahead.

What is the purpose of prefetch? ›

Prefetch files are used by Windows to store information in relation to software activity, including the number of times software has run and associated files used by the software.

How much cache should SSD have? ›

Volume SizeMinimum Size of SSD Cache
< 24 TB400 GB
24 TB - 40 TB800 GB - 960 GB
40 TB - 80 TB1.92 TB
> 80 TB3.84 TB
Jul 27, 2021

Does SSD increase speed or RAM? ›

There are two reasons for that difference in speed. First, the memory chips in SSDs are slower than those in RAM. Second, there is a bottleneck created by the interface that connects the storage device to the computer. RAM, in comparison, has a much faster interface.

Does defragmentation improve performance SSD? ›

To summarize, do not defrag an SSD

The answer is short and simple — do not defrag a solid state drive. At best it won't do anything, at worst it does nothing for your performance and you will use up write cycles. If you have done it a few times, it isn't going to cause you much trouble or harm your SSD.

Is SysMain necessary? ›

Luckily, it isn't an essential system process and can be disabled if necessary. If you think that SysMain is causing you issues, it's better to disable it. Using our methods below, you can find a solution to help restore your computer.

Is it okay if I delete Prefetch files? ›

You can also delete Prefetch files, which are created by the operating system each time an app is launched for the first time. These files are designed to make apps open faster and don't use too much disk space, but if you're running low, you can delete them without causing any problems.

Can data prefetching be harmful for the performance of a system? ›

Prefetching hazards. A naive deployment of a data prefetcher not only may not improve the system performance but also may significantly harm the performance and energy efficiency [9]. The two well-known major drawbacks of data prefetching are (1) cache pollution and (2) off-chip bandwidth overhead.

How do I reduce memory usage on Windows 11? ›

How to free up RAM in Windows 11
  1. Task Manager.
  2. Uninstall unused programs.
  3. Reduce background applications.
  4. Clean page file.
  5. Swapping images for performance.
  6. Make sure your computer is malware-free.
Nov 7, 2022

Should I disable SysMain for gaming? ›

There are no side effects if you decide to turn it off. If your system is running well, leave it on. But if you have high HDD usage issues, high RAM usage, or degraded performance during RAM-heavy activities, try turning it off and see if it helps. If it does, keep it off.

What is the new name for SuperFetch? ›

In the latest versions of Windows 10, the Superfetch service now shows up under the name SysMain. In the Task Manager, it shows up as Service Host: SysMain. If you're running an older version of Windows 10 or any version of Windows 7 or 8, this will show up in the Task Manager as Service Host: Superfetch.

Should I turn off drive optimization for SSD? ›

You shouldn't optimize or defrag your SSDs, as it does nothing for the drive's performance. On the contrary, it can decrease your SSDs lifespan.

Should you keep your SSD full? ›

The rule of thumb to keep SSDs at top speeds is never completely to fill them up. You should never use more than 70% of the total capacity to avoid performance issues. When you get close to the 70% threshold, you should consider upgrading your computer's SSD with a larger drive.

Does SSD improve overall performance? ›

SSDs work without moving parts, giving them an advantage over HDDs. Games launch and levels load faster when installed on an SSD. SSDs provide a smoother experience in games that stream assets from storage.

How to improve SSD performance? ›

Top 7 Tips to Get the Most from your SSDs
  1. Enable TRIM. TRIM is essential for keeping SSDs in tip-top shape. ...
  2. Don't Wipe the Drive. ...
  3. Update Your Firmware. ...
  4. Move Your Cache Folder to a RAM Disk. ...
  5. Don't Fill to Full Capacity. ...
  6. Don't Defrag. ...
  7. Don't Store Large Files.

What can ruin an SSD? ›

SSDs require a capacitor and power supplies, which are vulnerable to malfunctions—especially in the case of a power surge or power failure. In fact, in the case of a power failure, SSDs have been known to corrupt existing data, too, even if the drive itself hasn't failed completely.

How do I optimize my SSD for Windows 11? ›

Optimize Your SSD on a Schedule
  1. Search for “Defrag” and click Defragment and Optimize. (Image credit: Tom's Hardware)
  2. Click the Change settings button. (Image credit: Tom's Hardware)
  3. Set how often you want Windows 11 to optimize your SSD.
Feb 19, 2023

How do I manage my SSD in Windows 11? ›

#2. Set Up SSD
  1. Shut down the computer, open the computer case, connect and insert the new SSD (M. 2 or NVMe) into the SSD slot and fasten it with screws.
  2. Close the computer case and reboot the PC.
  3. Press Windows + R keys, type diskmgmt.
  4. Right-click on the new SSD, select Initialize Disk, and select GPT as the disk type.
Jan 12, 2023

How do I defrag my SSD Windows 11? ›

To defragment your hard disk
  1. Open Disk Defragmenter by clicking the Start button. . ...
  2. Under Current status, select the disk you want to defragment.
  3. To determine if the disk needs to be defragmented or not, click Analyze disk. ...
  4. Click Defragment disk.


1. Any solid reason to turn off Superfetch and Prefetch for SSD? (2 Solutions!!)
(Roel Van de Paar)
2. How to Disable 'Superfetch' on Windows 10 and Windows 11
3. How to Disable Superfetch / SysMain in Windows 10
(The Geek Page)
4. How to Disable Superfetch in Windows 11
(The Geek Page)
5. How to FIX 100% Disk utilization | Sysmain Superfetch
(Enrique Cal Tech)
6. ✅ How To Fix SysMain Service High Disk Usage in Windows 11
(Vikram Kumar Singh)
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