Windows 10 和Windows 11是出色的操作系统。但是，如果您看到性能持续低迷，则可能是因为称为SysMain（以前称为Superfetch）的东西。
在本文中，我们将帮助您了解SysMain以及为什么您可能会遇到此服务的高磁盘使用率问题。
什么是 SysMain（Superfetch）？
Superfetch在(Superfetch)Windows 10 1809 更新后被称为 SysMain ，是随Windows Vista引入的，是(Windows Vista)Prefetch的继承者（ Windows XP中的类似功能）。随着时间的推移，操作系统使用此功能来提高系统性能。
为什么随着时间的推移？首先，它会研究您的RAM使用模式。然后，该功能会识别您最常在 PC 上运行的程序。一旦Superfetch获得此信息，它就会将这些程序预加载到您的RAM中。当您启动这些程序时，您会发现它们的加载速度要快得多。
所以，Superfetch需要资源。当您在任务管理器(Task Manager)中查看系统进程列表为“服务主机：SysMain”
时，您可能会发现Superfetch在后台工作：(Superfetch)
至关重要的是，Superfetch不会剥夺其他程序的RAM。它只使用未使用的RAM。在RAM(RAM)空间方面，任何(Any)新启动的程序仍将优先于Superfetch 。如果需要，Superfetch将为另一个应用程序释放 RAM(free up RAM)。
如果您认为Superfetch导致您的计算机出现性能问题，您可以安全地禁用它。下面，我们讨论几种禁用Superfetch和修复Service Host的方法：SysMain高 CPU 使用率问题(high CPU usage problem)。
从服务中禁用 SysMain
由于SysMain是Windows服务，禁用SysMain的最简单方法是从服务(Services)控制台：
- Press Win + R，键入 services.msc，然后按Enter启动服务(Services)控制台。
- 滚动(Scroll)服务(Services)控制台中名为SysMain的服务的列表。
- 双击(Double-click)SysMain服务(SysMain)以打开服务属性。或者，您可以右键单击服务并选择属性。
- 选择停止(Stop)按钮以停止服务。然后，展开Startup Type下拉菜单并选择Disabled。
- 选择确定保存并退出。
使用命令提示符禁用SysMain(SysMain Using Command Prompt)
使用命令提示符(Command Prompt)禁用SysMain更快。如果您习惯使用命令，以下是禁用SysMain的方法：
- Press Win + R，键入 cmd，然后按Ctrl + Shift + Enter启动提升的命令提示符(Command Prompt)。
- 将以下命令复制并粘贴到命令提示符(Command Prompt)窗口中，然后按 Enter：
sc stop “SysMain” & sc config “SysMain” start=disabled
从注册表中禁用 SysMain
如果以前的方法由于某种原因不起作用，您可以修改注册表设置以禁用 SysMain：
- Press Win + R，键入 regedit，然后按Enter启动注册表编辑器(Registry Editor)。
- 使用左侧边栏导航到以下路径，或将以下文本复制并粘贴到顶部的导航栏中，然后按 Enter：
HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesSysMain
- 在右窗格中搜索名为Start的值并双击它。
- 将Value Data 更改(Change Value Data)为 4 并选择 OK 保存并退出。
运行 SFC 扫描
如果您想尝试在不禁用 SysMain 的情况下解决SysMain高(SysMain)磁盘使用率问题，您可以尝试使用系统文件检查器(System File Checker)( SFC )。
SFC是(SFC)Windows上的内置实用程序，用于检查系统文件的完整性。它会自动替换它在扫描期间发现的损坏的系统文件，因此如果系统文件损坏是问题的根源，SFC可能会修复它。
- Press Win + R，键入 cmd，然后按Ctrl + Shift + Enter。
- 将以下命令复制并粘贴到命令提示符(Command Prompt)中，然后按 Enter(Enter)：
证监会 /scannow
扫描将扫描您的硬盘以查找损坏的系统文件并替换已损坏的文件。扫描完成后，重新启动 PC 并检查Service Host SysMain高磁盘使用率问题是否仍然存在。
更新视窗
检查Windows 更新(Windows Update)并查看是否有可供下载的更新始终是必不可少的。微软(Microsoft)一直在寻找Windows的问题并发布更新来修复它们。
如果以前的修复没有帮助，更新可能值得一试：
- Press Win + I 启动设置(Settings)应用程序，然后从左侧边栏中
选择Windows 更新。(Windows Update)
- 选择检查(Check)更新按钮。
- 如果有可用更新，请选择下载(Download)并安装按钮进行安装。
重新启动您的电脑，看看是否能解决问题。
用 SSD 替换硬盘
如果您已经使用旧机械硬盘(HDD)一段时间了，将其更换为固态硬盘(Solid State Drive)( SSD ) 可以优化您的计算机性能并解决磁盘使用率高的问题。
如果您尝试了故障排除并用尽了所有方法来解决问题，这可能是特别有必要的。
大多数现代计算机都有一个插槽来容纳SSD(SSDs)。但是，如果您从未购买过SSD(SSDs)，请使用我们的SSD 购买指南(SSD buying guide)做出明智的决定。
SysMain 磁盘使用情况，规范化
希望您能够通过这些修复程序之一修复SysMain磁盘使用情况。SysMain不一定是资源消耗者。Windows 引入了此智能功能，以优化RAM使用并在使用最常用的应用程序时提供更快的性能。
如果它使用大量内存，您可以永久禁用它而不会产生严重后果。或者，修复系统文件损坏或Windows更新可能有助于在不禁用SysMain服务的情况下解决问题。
How to Fix Service Host (SysMain) High Disk Usage in Windows 11/10
Windоws 10 and Windows 11 are excellent operating systems. Βut if you see a consistently sluggish performance, it could be because of something called SysMain (earlier known as Superfetch).
In this article, we help you understand SysMain and why you might face a high disk usage problem with this service.
What Is SysMain (Superfetch)?
Superfetch, called SysMain after the Windows 10 1809 update, was introduced with Windows Vista and is a successor to Prefetch (a similar feature in Windows XP). The OS uses this feature to improve system performance over time.
Why over time? First, it studies your RAM usage patterns. Then the feature identifies programs you run most often on your PC. Once Superfetch has this information, it preloads these programs into your RAM. When you launch these programs, you’ll see them load much faster.
So, Superfetch needs resources. You might find Superfetch working in the background when you look at the list of system processes in the Task Manager as “Service Host: SysMain”:
Critically, Superfetch doesn’t deprive other programs of RAM. It only uses unused RAM. Any newly launched program will still have priority over Superfetch regarding RAM space. If required, Superfetch will free up RAM for another app.
If you believe Superfetch is causing performance issues on your computer, you can safely disable it. Below, we discuss a few ways to disable Superfetch and fix Service Host: SysMain high CPU usage problem.
Disable SysMain from Services
Since SysMain is a Windows service, the simplest way to disable SysMain is from the Services console:
- Press Win + R, type services.msc, and press Enter to launch the Services console.
- Scroll through the list in the Services console for a service named SysMain.
- Double-click on the SysMain service to open service properties. Alternatively, you can right-click on the service and select Properties.
- Select the Stop button to stop the service. Then, expand the Startup Type drop-down menu and select Disabled.
- Select OK to save and exit.
Disable SysMain Using Command Prompt
Using the Command Prompt to disable SysMain is quicker. If you’re comfortable using commands, here is how you can disable SysMain:
- Press Win + R, type cmd, and press Ctrl + Shift + Enter to launch an elevated Command Prompt.
- Copy and paste the following command into the Command Prompt window and press Enter:
sc stop “SysMain” & sc config “SysMain” start=disabled
Disable SysMain from the Registry
If the previous methods don’t work for some reason, you can modify the registry settings to disable SysMain:
- Press Win + R, type regedit, and press Enter to launch the Registry Editor.
- Navigate to the following path using the left sidebar or copy and paste the following text into the navigation bar at the top and press Enter:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SysMain
- Search for a value named Start in the right pane and double-click on it.
- Change Value Data to 4 and select OK to save and exit.
Run SFC Scan
If you want to try resolving the SysMain high disk usage issue without disabling SysMain, you can try using the System File Checker (SFC).
SFC is a built-in utility on Windows that checks system file integrity. It automatically replaces the corrupt system files it finds during the scan, so if system file corruption is at the root of the issue, SFC might fix it.
- Press Win + R, type cmd, and press Ctrl + Shift + Enter.
- Copy and paste the following command into the Command Prompt and hit Enter:
sfc /scannow
The scan will scan your hard disk for corrupt system files and replace ones that have become corrupt. Once the scan completes, restart your PC and check if the Service Host SysMain high disk usage issue persists.
Update Windows
It’s always essential to check Windows Update and see if an update is available for download. Microsoft is constantly looking for issues with Windows and releases updates to fix them.
If the previous fixes weren’t helpful, an update might be worth a shot:
- Press Win + I to launch the Settings app and select Windows Update from the left sidebar.
- Select the Check for updates button.
- If updates are available, select the Download & install button to install them.
Restart your PC and see if that fixes the problem.
Replace Hard Drive with SSD
If you’ve been using your old mechanical HDD for a while, replacing it with a Solid State Drive (SSD) can optimize your computer’s performance and solve the high disk usage issue.
This might be especially warranted if you’ve tried troubleshooting and exhausted all methods to fix the issue.
Most modern computers have a slot to accommodate SSDs. However, if you’ve never purchased SSDs, use our SSD buying guide to make an informed decision.
SysMain Disk Usage, Normalized
Hopefully, you were able to fix SysMain disk usage with one of these fixes. SysMain isn’t necessarily a resource-hog. Windows introduced this intelligent feature to optimize RAM usage and deliver faster performance when using the most frequently used apps.
You can permanently disable it without severe consequences if it’s using a lot of memory. Alternatively, fixing system file corruption or a Windows update might help resolve the issue without disabling the SysMain service.
