High CPU usage

Avast Free Antivirus / Premium Security
1

Hey,

In the last weeks, Avast has been using a noticeably high amount of CPU - like 7-15% on a 13700k, and makes the whole system fell sluggish.
If I restart the computer it goes away for a while, but it will eventually come back after a random amount of time.

Avast Premium Security Version: 24.8.6127 (build 24.8.9372.870)
CPU: 13700k
OS: Windows 11 Pro 23H2 22631.4037

Could you please help?

Ty

1 Like
2

Maybe a clean install will fix it. That means uninstall Avast, use the cleanup tool, and do a fresh install and config.

Annoying yes, but probably faster than guessing what’s borked.

3

I forgot to add that after a while, if I try to disable the shields, the UI freezes, and it’s impossible to interact with the app any longer.
I’m pretty sure it’s still running in the background, but I can’t interact with it in any way.
And I forgot to add it, but in normal operation, avast only take 0-1% CPU on my system.

1 Like
4

%40 and up CPU usage after last update. Also slow down internet connection. Is it normal?

Intel(R) Core™ i7-8650U CPU @ 1.90GHz 2.11 GHz
16 GB RAM
Windows 11

5

If two or more AV’s are active at the same time, they might get triggered by each other. You end up with duelling AV’s eating up CPU cycles.

This is probably not what’s going on. Think what software might have changed the last couple of weeks. For instance a search tool indexing which then causes Avast to scan every file it reads. Something like that.

Or maybe it’s heuristics being silly. You could try running without Behavior Shield and see if that solves the problem.

6

Real time protection is off, but I don’t know why that would cause increase cpu load in avast.
And its specifically AvastSvc.exe

7

Is Defender still running maybe?

8

I’m seeing one core fully utilised by avastsvc.exe, seems to have started after an avast update. Disabling the shields for 10min had no effect except now the UI no longer responds. I’m now regretting having paid for it.

9

Well, I fixed it by removing it and replacing it with something that actually works.
I see no interest towards finding out what actually causes the issue, which means there is no chance that it will actually be fixed, so I can’t use the product any longer.
It’s a shame really, as I was really satisfied with the product, aside from the annoying popups, and I have personally installed it on dozens of computers.
I’m saddened to see that the company learned nothing since the issues with the firewall causing BSODs, where the only workaround was un-installing the firewall.
Well, I wish you all the best of luck with your future endeavors.

10

Any solution on this?, same problem here.

11

WHY ISN’T AVAST RESPONDING?
Most people here bought an Avast Product and are entitled to expert guidance from this company.

12

This has been my experience. The CPU usage went down after an Avast application update. It still seems to like hogging too much CPU but, when I notice this I just reboot my machine and it fixes it. Hope this helps. Seems potentially something is getting hung in Avast to cause this as I have tried turning off all shields while it’s happening and the issue persists until I reboot which turns the shields back on but the CPU % goes down. I found a easy way to detect when this is happening is to setup a custom fan curve for your fans based on CPU temp. Could take some digging to find what CPU temp Avast drives your system to while the issue is occuring.

13

It sounds like Avast might be running background scans or experiencing a bug. Try these steps:

  1. Check Background Scans – Open Avast and disable unnecessary real-time scanning features.
  2. Update or Reinstall – Ensure Avast is fully updated or try reinstalling it.
  3. Check Task Manager – See if any specific Avast process is causing the high CPU usage.
  4. Try Another AV – If the issue persists, consider switching to Windows Defender, which is lighter on resources.

Let me know if this helps!