Antivirus signature update causes high HDD and RAM usage and makes PC very slow

I have this problem on multiple computers, and I know of other people who also have the same issue.

When CIS upgrades the AV database there is a lot of HDD activity for a long time and the RAM usage of cmdagent.exe goes quite high

I don’t think it’s the PC as mine is not a slow system (P4 3Ghz with HT, 1GB RAM) yet CIS causes terrible lag for at least a minute or two (often much more) when it updates.

I think you need to change the way the updates work, it seems there is something wrong here

I’ve managed to lessen its impact by turning off AV auto-update before real-time scanning and scheduling a daily scan on an empty folder.

Unless I’ve missed something, Comodo Support Staff have been remarkably quiet about this problem, which (as you say) has been brought up several times before. They should respond timely to problems like this.

In about a week or 2 the DB is going to start shrinking in size, and should help with this problem

Shrinking aye… I hope you are not going to start cutting signatures out :wink:

If its using massive RAM and HDD all the time, its a bug.

But currently from what i can read its not a bug, it kind of a design flaw. But they are working on getting the AV DB smaller starting in next week and a even smaller in v4.0

No, the high RAM and HDD usage only occurs when the AV database gets updated.

I think you are correct, there is some kind of design flaw in the way the updates and/or the AV database works.

I have to agree this is becoming a nightmare, especially on computers that haven’t been switched on for a while.

It used to take a couple of minutes to update and during that time the computer would be very, very slow and unusable, but after the update were fine.

Now it seems to be taking longer and longer each time, the other day it was an hour! That may be OK on a desktop PC, I can turn them on and then do something else, but on a laptop with a 2 hour battery life, it’s no joke.

I have used many AV products but none have ever crippled the system this way during an update. Hopefully this is something that is going to be fixed, as other than this, I am quite happy with Comodo.

Hi there, I am a complete novice and have no idea about computers. All I do know is that when i clicked on “update” my laptop has nearly come to a stand still? ironically the forum site is normal? perhaps someone could reply with a solution? I have re-installed once and it seemed to work for 10 mins, then updated and back to square one :frowning:



I too am no computer expert and a lot of the language used here is completely above my understandiing,

My problem is everytime the antivirus updates -which seems to be at least twice an hour (which seems excessive and it didn’t used to do it more than a few times a day until the last few days) My CPU useage is at 100% as soon as it updates freezing all my browsers email or whatever and the only way I can get out of it is to Ctrl/Alt/Delete and even then the task master takes forever to clear the problem. Often the only way out is to reboot, then the computer works fine until the antivirus updates again and it all starts freezing again.

Can someone please tell me in simple terms how this can be resolved or if not when the problem will be fixed as I’m seriously thinking of removing the comodo antivirus and going back to only the firewall and get another free antivirus from elsewhere. Before this happened I was loving comodo but this has seriously dented my confidence in it :frowning:

Yes, AV updates have started to hurt people like us. My 3GHz - 2GB Ram PC just succumbs to the update and is rendered paralysed every half an hour. CPU is 100% and huge HDD activity just during updates.

I like comodo products a lot, and a big FAN.

Hi Guys

Please read here:


Well I’ve read that bugs forum you linked to and I can’t understand most of it or the fixes it suggests, could someone please tell me when the antivirus updates are going to be fixed as I can hardly use my pc when its updating, Surely someone can give me an answer in plain language and a time when it is going to be fixed, it is driving me insane. ???
XP 64 bit sp 2 no other security installed

Hi Meryltwin,

That thread I posted directs you do the bug reports thread for CIS 3.10. version 3.10 is the last version of the version 3 series before CIS 4.0, So we are now collecting bugs in one place so if an emergency fix needs to be out, it will be out in a 3.10 Build BEFORE 4.0, Other bugs will be taken into consideration so they don’t happen in 4.0. It is easier to have it in one place, Since v4 is quite a few months away and developers are watching just “one thread” for any emergency bugs that need fixing now, Or ones that can be left for v4.


Seems this problem is still well alive at this date… >:( It should already have been fixed, or more to the point, this kind of problem should never have existed. I can walk away from the computer and do something else for the 15 minutes it’s rendered useless by the update… Much harder is to convince my non-technical wife that we do not need a faster computer, all we need is that somebody fixes a piece of software.

I agree.

The problem is so grave that I had remove CIS from 2 of my home PC’s and stopped the updates on another 2 as its practically impossible to survive the update duration.

And so far looks like CIS team has not considered it as an emergency bug.

Real problematic guys.

I agree with most comments.

I have xp and ubuntu 9.04 on my notebook, and after using ubuntu for a week and start the pc from XP, antivirus comodo took 15 minutes to update the database, at which time the computer was unusable.
Solution: I uninstall the antivirus, left firewall with D + proactive and install avira free, until the Comodo dev. team resolves this problem with comodo updates the antivirus database.
Comodo antivirus works ok, is fast and lightweight but the updates is a nightmare.
Anyway at the moment I am learning to use ubuntu.


Your right it slows down the PC a ton, the DB is going to shrink, and v4 will have a new DB format, that will fix this design flaw and shrink the DB even more.

I hope so, this is the only problem I have with CIS at the moment (apart from how I think BOClean integrated should have its own options in the program…)

But currently this update problem is ridiculous. I really hope that this problem will be solved because I really like CIS and want to use it but currently I can’t!!

The same routine for me. During update comp is totally useless.
Its weird that during update bases.cav gets overvriten so many times !!! Funny stuff starts when progress meter shows 51%. bases.cav grows from 0 to ~103MB and then starts it all over again - file size gets 0 again ang grows all way up to 103 megs. In each of these cycles PC gets unresponsive for a while. There is 0 network activity. So I am thinking that something goes wrong in DB update procedure…

From observing the behaviour of the update, it seems to me that the virus signature database is not a database at all in any modern sense. It’s like it’s just an array of bytes, and any modification requires a complete rewrite of the file… Oh, I’m getting flashbacks of magnetic tapes… :wink: