If you’ve ever been working on your PC, and noticed that suddenly everything you do seems to be extremely slow, there could be a number of factors causing this behavior. One possibility is that your hard drive is working too hard. One of the symptoms you might see is that any action you perform can take several seconds or longer before you get a response. For example, clicking on a file to open it may take much longer than normal to open the file, or maybe switching between apps takes longer than usual. These are all possible signs that your hard drive is maxing at 100% utilization or close to that.
To check, you can go into Task Manager and see what the current real-time disk utilization is:
Right-click anywhere on your taskbar at the bottom of your screen and select "Task Manager.".
When Task Manager opens, look at the Processes tab and check the "Disk" column:
If you see the Disk at 100% or consistently above 90%, there is a good chance your slow performance is due to the disk usage.
Fortunately, if you should ever see this, there are a few things you can try to resolve it. The solution for you may be one or a combination of these things, so the best thing to do is just go down the list trying each one until the high utilization goes away.
Method 1: Reboot
Method 2: Disable Anti-virus Software
Method 3: Fix for Known Issue with StorAHCI.sys Driver
Method 4: Disable Search and Superfetch
Method 5: Run Chkdsk (Check Disk)
Method 6: Check Virtual Memory Settings
The universal fix for many issues in Windows is, of course, to simply reboot the PC. If you find that your disk utilization is running higher than normal, a good first step to troubleshooting is to just restart. I recommend using the "Restart" option rather than shutting down, since by default the "Shut down" option in Windows 10 does not completely shut down the computer, but instead puts it into a hibernation state for quick booting.
Restarting the PC will hopefully kill any processes that were running out of control and using up disk activity. It could be an application or process that was "hung" and a reboot should take care of that.
If after rebooting, you find that your disk utilization is still at or near 100%, then move onto the next method below.
If you have anti-virus software installed, it’s possible that an in-progress virus scan could be impacting your hard drive’s performance as it scans your file system. To see if this is the culprit, you can try temporarily disabling the anti-virus software. You may need to consult the documentation of your particular software in see how to do this, but in many cases you can check the system tray in the lower-right corner of your Windows taskbar.
Most anti-virus applications will have an icon visible in the system tray. You can try clicking or right-clicking on the icon to see if there is an option for pausing or disabling the service. In some cases, you may need to open the software and see if there is an option for pausing or disabling the service.
Microsoft has released an article describing a known issue with some storage devices that are Advanced Host Controller Interface PCI-Express (AHCI PCIe) models running with the inbox StorAHCI.sys driver on Windows 10. This issue can result in 100% disk utilization in Task Manager. This is due to a bug in the firmware for these storage devices when Message Signaled Interrupt (MSI) mode is enabled.
To check on your system, follow these steps:
Open Device Manager by typing "Device Manager" into the Search box next to the Start menu, then clicking on "Device Manager" in the results:
When Device Manager opens, click on "IDE ATA/ATAPI controllers" to expand the selection. If you have an AHCI controller, such as "Standard SATA AHCI Controller" in this example, then double-click on it to get to the "Properties" window (or right-click and select "Properties").
On the Properties window, select the "Driver" tab. Then click on the "Driver Details" button.
On the "Driver File Details" screen, take note of the name of the driver file. If it is "storahci.sys" as in the example below, then you know that you are using the affected driver:
Close the "Driver File Details" window, and click on the "Details" tab of the AHCI controller Properties window. Change the "Property" drop-down menu to "Device instance path," then take note of the path in the "Value" box - everything after the "PCI\" beginning with "VEN_". There are two unique strings, the first begins after "VEN_" and ends with the slash ("\"), highlighted in yellow below. The second unique string begins after the slash ("\"), highlighted in green below. You will use this path in step 7.
Open the Registry Editor by typing "regedit" in the Search box next to the Start menu.
Once the Registry Editor is open, use the left-side navigation to find the following path: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\PCI\VEN_<Unique string from step 5>\<Second unique string from step 5>\Device Parameters\Interrupt Management\MessageSignaledInterruptProperties
Double-click on the key called "MSISupported" and change the "Value data" field to a value of "0."
Reboot the PC and see if the disk utilization goes down.
There are two Windows Services that have been known to cause high disk utilization. One of these is Windows Search. This service runs to help speed up the process of searching for files on the file system. It does this by creating and maintaining an index of all of the files on the computer, but this process can sometimes cause the hard drive to be extremely busy. Try disabling Search by following these steps:
Open Windows Services by typing "Services" into the Search bar next to the Start menu:
When the Services window opens, locate "Windows Search." Right-click on it and select "Stop."
Watch the disk utilization in Task Manager to see if it goes down. If so, then you can choose to disable the Windows Search service altogether so that it does not start up again when the computer restarts. If you do not use WIndows Search, or if you do not mind the searching taking a little longer (since files will not be indexed), then it would be a good idea to just disable the service (you can re-enable it at any time). To do this, follow these steps:
Right-click on Windows Search in the Services window, and select "Properties."
Select "Disabled" from the "Startup type" drop-down menu.
There is another Windows Service called "Superfetch," which is there to help manage RAM and ensure the PC uses it efficiently. It mainly helps improve boot times and also helps applications load more quickly. While these are good things, Superfetch has been known to cause high disk utilization. To stop and disable the service, follow the same steps from above (for the Windows Search service), but in Step 2 look for the service called "Superfetch." Follow the same instructions as above to stop and disable the service if needed.
High disk utilization can also be an indicator of a problem with your hard drive. There are several applications on the market that you can use to check your hard drive for problems, but Windows also has a built-in utility called “chkdsk” that will scan your hard drive for errors and attempt to fix them.
You can run this utility by following these steps:
Open an administrator Command Prompt by typing "cmd" into the Search box next to the Start menu. Then right-click on "Command Prompt" in the results at the top and select "Run as administrator."
Say "Yes" to the User Account Control prompt:
At the command prompt, type "chkdsk /f /r"
The "f" command tells the utility to fix any errors found on the disk. The "r" command tells it to locate bad sectors and recover any readable information. Since you are running the chkdsk command on the same hard drive that the operating system is running on, you will see a message indicating that you cannot run the process until the next time the PC starts. Just type "Y" and then reboot to kick off the chkdsk process.
Once the chkdsk process finishes, it may show that it found some errors and should have attempted to fix them. Now go ahead and check Task Manager to see if the disk utilization is better.
Virtual memory is an area of the hard drive that is used to supplement the physical memory (RAM) in your computer. When you don’t have enough RAM, Windows will store data in this virtual memory space and then swap it back to the RAM when needed. You may need to check these settings and set some manual values rather than have Windows manage these settings. In some cases, this can cause high disk utilization if the settings are not managed properly.
Open Control Panel by typing "Control Panel" in the Search box next to the Start menu.
Once Control Panel opens, click on "System and Security."
Click on "System"
On the "System" screen, click "Advanced system settings."
On the System Properties window, click on "Settings..." under the "Performance" section:
On the Performance Options window, click on the Advanced tab. Under the "Virtual memory" section, click on "Change..."/p>
On the Virtual Memory window, follow these steps:
Be sure to uncheck the box for "Automatically manage paging file size for all drives."
Select the hard drive that your Windows operating system is installed on, typically this is your "C" drive.
Select the "Custom size" radio button, and enter kInitial size and Maximum size values in MB. It’s best to use the recommended value shown at the bottom of the window for the Initial size. The Maximum size should be set to 1.5 times the amount of physical RAM you have installed in the PC. For example, if you had 8GB of RAM, you would enter 12,288 MB (1.5 x 8 x 1024 = 12288).
Click on "Set"
Click on "OK"
Reboot your PC and check the disk utilization now in Task Manager.
By following one or more of the methods above, you will be able to locate the root cause of the high disk utilization in Task Manager, and resolve the issue. You may not need to go through each method, but the issues mentioned above have been known to typically cause this behavior. The hope is that by following all of the steps above, you will track down the cause and improve the performance of your PC.