Every now and then I am getting mouse lag that lasts for 30 seconds or so accompanied by AvastSvc.exe using 2-10% of CPU (normally at 0.1-0.5%). I think the problem is related to the real time shields.
What os/sp?
What exact version of avast?
Have you disabled the shields one at a time to see if a specific shield is causing it?
Is it happening right after a fresh boot or only after using the system for a while?
By chance do you have a Logitech wireless? I’ve been experiencing something similar from time to time. Not for 30 seconds but about 10.
I have two Logitec wireless laser mice (on XP Pro and win7 systems) and don’t experience that lag.
Windows 8.1 on a fresh install.
Avast 2015.10.0.2208
I don’t know how to disable the shields one at a time but disabling all and starting them again fixes the lag.
It does not happen right after a fresh boot but seemingly random.
The mouse I’ve used for at least a year on my laptop with Avast without problem.
- Which Avast…? (Free/Pro/IS/Premier)
- Other security related software installed…?
- Which AV(s) did you use before Avast…?
I’ve also had this happen. Normally out of nowhere, the mouse just stops for a few seconds then comes back like nothing happened.
Just changed from a Logitech M315 to M185 but no change.
I’ve reported this to the Moderators. Hope they’ll take a look.
OP said they were using this setup for a year without a problem and so have I… this just started fairly recently. In my case I have:
Avast Free 2015.10.0.2208
Malwarebytes Anti-Malware
Malwarebytes Anti-Exploit
Win Patrol
AdFender
Win 7 64 bit Pro
As Bob reported it, wait for one of the devs.
I got it last night while on Skype, have had freeze up before but blamed other apps and startups…
Avast free 2015.10.0.22.8 defn 150110.2
EEEPc W7 starter, no previous AV
too much monitoring too often, used to use other AV on another machine and I dropped it because of what AVAST is doing now, using too many scarce resources… Might have to get a different one again…
ADD: after reading Post #10 Logitec wireless mouse is used
Only avast can tell ofcourse,
but it may very well be this problem is solved in the next release.
They said it would be released this month,
but a few days ago I read a post form a avast member that it will be next month.
As far as I can tell it only seem to happen with certain (brands?) wireless mouses.
Note: I also use a Logitec wireless mouse, but no problems here.
Did you install Logitech SetPoint software on your Windows 8.1 installation? SetPoint will install right mouse drivers for you as well as silent firmware update for mouse and receiver if needed. Maybe you have issues with old firmware on the receiver especially if you’ve got an “Unifying” model. Windows 8.1 drivers are good but they not provide micro firmware for receiver and mouse (not even via Windows update). This kind of lag could be not Avast related but some kind of radio issue. Please also be sure to install a proper usb filter driver for your motherboard chipset (if provided) and also be sure not to connect the receiver on a usb 3.0 port (several issues have been reported by Logitech too). Install on usb 2.0. Try all these and the we could investigate a little more on Avast. Btw I’ve got a wireless M505 mouse on Windows 8.1 64 bit with logitech Setpoint latest version and Avast Internet Security having no issues.
I’m using setpoint, but I think the focus can be taken off the actual mouse itself. Everyone is getting bogged down in trying to troubleshoot the mouse and mouse drivers now.
The issue is not really that the mouse is lagging, it’s just the most noticeable thing that occurs. What the real issue seems to be is that something is taking 100% of resources for a brief period which causes the cursor to freeze on the screen and the mouse to become non responsive. However, I also see heavy hard disk activity when this occurs.
The fact that at least four avast users are on here concurring should be the most prudent indicator at this point.
I was guilt of both offenses. Using USB3 and had SetPoint disabled.
I’ve seen the errors of my ways and will see if getting back on the straight and narrow will resolve the problem. 
For now, I’ll leave SetPoint running however, this is what Logitech has posted on their site:
"When you don’t need SetPoint
SetPoint is not required for the following mouse functions that are built into Windows® 8: Left click
-
Right click
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Middle click*
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Back/forward buttons for navigating Web pages
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Scrolling**
-
If you want to assign other functions to your mouse buttons, then you can use SetPoint to change their functionality."
Just FYI - this just happened on my laptop which is not Logitech, it’s a Synaptics touchpad.
As mentioned, the entire system locks up for about 10 seconds… the mouse cursor does freeze (which is the reason this thread says mouse lag as it is seemingly only the mouse cursor that’s frozen and most visible), but I verified visually that avast was in the middle of scanning something as the system tray icon was caught mid flip per se. Im sure if I banged on my keyboard nothing would respond either.
Update: And now it just happened on my desktop with the Logitech and again Avast was scanning something AND the system tray icon was stopped mid flip AND I hit the keyboard and nothing responded.
It’s an Avast thing…