Windows 10



Windows 10 - Task Manager Reports 100% Disk Utilization

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This article addresses a Windows 10 issue where Windows Task Manager might show 100% disk utilization on devices with Message Signaled Interrupt (MSI) mode enabled.

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Symptoms of this issue include the following:

• Task Manager reporting the hard disk to be operating at 100% utilization despite a light workload or no workload.
• The system may experience lag or become unresponsive.
• The system event log contains numerous events with Event ID 129, which represent resets of the disk controller.

Microsoft reports that an issue exists with some Advanced Host Controller Interface PCI-Express(AHCI PCIe) models that causes these symptoms in Windows 10 when running with the StorAHCI.sys driver. Due to a suspected firmware incompatibility, the Solid-state drive (SSD) does not properly complete input/output operations when Message Signaled Interrupt (MSI) mode is enabled in Windows 10.
As a result, the Windows storage stack attempts to reset the device after encountering unresponsive read or write commands over a period of time.

Microsoft has provided the following steps to disable MSI mode for specific devices via the registry:

1. Determine that the system is running the default AHCI driver (StorAHCI.sys):
   1. Open a command prompt with administrator privileges. Then type devmgmt.msc in the command prompt window and hitEnter.
   2. Under IDE ATA/ATAPI Controllers right-click on the AHCI controller node and selectProperties. This node is normally called "Standard SATA AHCI Controller."
   3. Click the Driver Details tab.
   4. If "StorAHCI.sys" is listed, the system is running the default driver.
   
   
2. Disable MSI for the controller in the registry:
   1. In the same properties window opened in step 1.2, navigate to the Details tab and selectDeviceinstance path from the Property drop-down menu. Note this path.
   2. Open the registry editor by typing regedit in the previously opened command prompt.
   3. Navigate to: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Enum\PCI\<AHCI Controller>\Device Parameters\Interrupt Management\MessageSignaledInterruptProperties, where <AHCI Controller> refers to the device instance path you noted in step 2.1.
   4. Change the value of the MSISupported key from "1" to "0".
   5. If you don’t know which controller your boot device is attached to, repeat steps 2.1 through 2.4 for all AHCI controllers found under 1.2.
   
   
3. Reboot the machine.

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If the steps above do not resolve the issue, the following steps may provide a workaround:

1. Navigate to Control Panel
2. Select System and Security
3. Select System
4. Select Advanced System Setting
5. Under Performance, Select Setting
6. Select the Advanced Tab
7. Select Change
8. Set the minimum to the amount of System Ram installed
9. Set the Maximum to double the amount of System Ram installed
10. Select Apply
11. Select OK
12. Restart the system

This process increases the size of the Pagefile that Windows uses to ensure enough storage space is allocated to the Operating System.