Reduce high CPU usage in Windows 10 caused by System Interrupts

If you have found out that system interrupts have a huge impact on CPU usage according to the Task manager statistics, then this guide will be useful to you as it explains how to find the root of the problem and neutralize it. You cannot remove System Interrupts form the Taskbar manager, but you can reduce CPU usage back to standard parameters (which is around 0.1-0.4%). In addition, you will understand what causes this abnormal behavior.

System interrupts is not a system process despite being displayed in the Process tab in your Taskbar manager. To put it simply – it is an event, which forces your microprocessor to stop doing currently active tasks in order to shift resources to another, «more important,» operations. There are various types of system interrupts but usually, the main «sponsor» of high loads is hardware interrupts (IRQ) and exceptions often caused by hardware malfunctions.

What to do with high CPU usage caused by System interrupts

In most cases, when you see unusual CPU usage stats in your Taskbar manager, the reason is either driver problems or malfunctioning component(s) of the computer. Although it is hard to reveal a correlation between driver issues or hardware with the problem, it is rarely related to something else. Before you start searching for the cause of the problem with high CPU usage, we suggest you think about your recent actions in Windows, the time before the problem:

  • For instance, if you have installed new drivers, you can try to roll them back.
  • If you installed new components or devices – check whether they are connected properly or not (also make sure that devices are not damaged including ports).
  • If you are 100% positive that the problem just appeared today and you didn’t change your hardware configuration at all, you can send your PC back in time to the latest system restore point.

Finding defective drivers that increase resource usage

As we already mentioned, the core of the problem is most likely in drivers or hardware. You can try to deduce what component causes the problem. It can be done with a freeware tool called LatencyMon.

  1. Download free home edition of LatencyMon from the official website http://www.resplendence.com/downloads. Install it and run the program.
  2. When in the main menu, click the «Play» button and go to the «Drivers» tab. Click on «DPC count» to sort out the entries on the list.
  3. Pay attention to the driver with the highest DPC Count. If it the driver for any external or internal device, it is highly likely that your high CPU usage problem was caused either by this driver or device itself (on the screenshot below you can see a «healthy» system – high DPC Count for the listed modules is normal).
  4. Open your Device Manager (right-click on the Start button and select it) and try to disable devices that have their drivers scored the highest on LatencyMon. After doing so, check if the problem still exists. [Important note: DO NOT disable system devices and those in «Processors» and «Computer» folders. We also advise against disabling your video card and input devices]
  5. If disabling of the particular device reduced high CPU usage back to normal, you need to make sure, whether that device functions properly or not. Also, try to update its drivers or roll them back (ideally, you should use drivers downloaded from the official manufacturer’s website).

According to statistics, the problem is usually caused by network adapter drivers, sound card drivers, and other devices for processing audio and video signals.

Alternatively, you can use another tool called DPC Latency Checker. It is compact and allows quick driver checks. DPC in the name of the program stands for the «Deferred Procedure Call.» When the system interrupts mechanism needs to stop tasks with lower priority, it relies on the DPC. DPC Latency Checker was developed to analyze how your system handles real-time video and audio signals by checking the latency of device drivers. You can use this app without installation, which makes the process even easier. Red bars on the screenshot below indicate dropouts caused by high latency – if you see them, something is wrong.

USB devices and controllers causing the problem

Another plausible explanation of high CPU usage caused by System interrupts – you have damaged external devices connected via USB ports (you may also have broken ports and corrupted cables as well. Don’t exclude simple device malfunction too). In this case, neither LatencyMon nor DPC Latency Checker will show anything unusual.

If you have any suspicions that the problem was caused by a USB device, we recommend you to disable all USB-controllers one by one in the Device Manager until you see a CPU usage drop in the Task Manager. But if you are an ordinary user with no technical knowledge of the system, it is possible that you may accidentally disable your mouse and keyboard. Be prepared for that and have an alternative way to re-enable the device!

Other reasons for high CPU usage by System Interrupts in Windows 10, 8.1 and Windows 7

We would also want you to know other possible reasons for this error to occur:

  • Enabled Fast Startup mode in Windows 10 or 8.1 in combination with the absence of original drivers for the chipset and power management. Solution: disable «Fast Startup» from the Control Panel’s menu «Power Options» (select «Choose what the power buttons do» – «Change settings that are currently unavailable» – uncheck «Turn on fast startup (recommended).»
  • Corrupted or uncertified (unoriginal) laptop power adapter – if disabling makes System interrupts go easy on your CPU, then here is your culprit. In some cases, however, the problem is caused not by the power adapter but the laptop’s battery (usually old one).
  • Disable Sound effects. Right-click on the speaker icon in the tray, click «Sounds,» then go to the Playback tab. Select the default device from the menu and click «Properties.» Go to the Enhancements tab, and disable all sound effects.
  • RAM malfunction – test the RAM using Windows Memory Diagnostic tool.
  • HDD/SSD malfunction – your computer may freeze for a second or two when accessing files and folders, while your disk reacts with strange sounds. In this case, scan your HDD or SSD for errors.
  • On rare occasion, some specific viruses that directly affect hardware might be the cause of the problem.

There is also another quick method to find the guilty component or device (but it is not very reliable as we know):

  1. Press Win+R on your keyboard and type perfmon /report. Hit Enter.
  2. Wait for the program to collect data and create a report.
  3. It should look like on the screenshot below

In the «Resource Overview» section you can check individual components marked with green and red colors. Pay extra attention to those in red. It is possible one of them is causing high CPU usage by affecting System Interrupts.

Update Your BIOS

BIOS is the first thing that loads when you start your computer or laptop. This tool helps your operating system to boot. For this method, you need to know your current BIOS version and check if there are any updates on the official manufacturer’s website. Instructions for installation should be there too. Updating BIOS is a serious procedure and requires technical knowledge of the process. If you are not sure, please don’t use this method.

To check your BIOS version, here is what you need to do:

  1. Press Win+R, type cmd and hit Enter.
  2. Type these commands: systeminfo | findstr /I /c:bios (press Enter) and wmic bios get manufacturer, smbiosbiosversion (press Enter). The «I» in the first command is a capital «I,» not L.

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