Regarding a weird RAM usage behaviour

[MURFING]

 I am not really able to tell wether it's normal or not, but I’ve noticed something a bit strange. My RAM usage increases by about 1 GB after doing a quick scan using the Windows Security system, and by around 4 GB or slightly more after doing a full scan.

 

The strange thing is that this extra RAM usage remains high even after the scan finishes, and it doesn’t go back down unless I restart the entire system.

 

At first, I got worried and thought it might be malware, but I repeated this experiment three times, and each time the RAM usage stays completely normal within the usual range until I run a quick scan or a full scan.

 

Is this normal behavior? Or could it indicate malware?

And even if there was malware, would it really only use an extra 4 GB of RAM? From what I know, malware typically consumes much more memory than that.

[Alex Atkin UK]

19 minutes ago, MURFING said:

 I am not really able to tell wether it's normal or not, but I’ve noticed something a bit strange. My RAM usage increases by about 1 GB after doing a quick scan using the Windows Security system, and by around 4 GB or slightly more after doing a full scan.

 

The strange thing is that this extra RAM usage remains high even after the scan finishes, and it doesn’t go back down unless I restart the entire system.

 

At first, I got worried and thought it might be malware, but I repeated this experiment three times, and each time the RAM usage stays completely normal within the usual range until I run a quick scan or a full scan.

 

Is this normal behavior? Or could it indicate malware?

And even if there was malware, would it really only use an extra 4 GB of RAM? From what I know, malware typically consumes much more memory than that.

Depends how you are measuring usage.  Recently opened files may remain in the RAM cache until you actually need to use that memory for something else.

[MURFING]

14 minutes ago, Alex Atkin UK said:

Depends how you are measuring usage.  Recently opened files may remain in the RAM cache until you actually need to use that memory for something else.

at first, I thought it might be malware or a virus, because unfortunately I was browsing on Google and I forgot that I had disabled UBlock Origin Lite, so an ad appeared. But I didn’t click on it or even go near it, and then I re-enabled UBlock Origin Lite again.
But obviously, no malware can infect my system just because an ad appeared, especially if I didn’t click on it, right?

And in general, there’s no malware that would only use 3–4 or 5 GB of RAM. Normally, malware would consume much more than that

[podkall]

RAM and Windows can cache useless files of already closed programs, but it will be among the first files it will unload if system needs more RAM.

 

It does that in case you ever open such program again, the files that would go to RAM are already there.

[Mark Kaine]

On 5/10/2026 at 7:40 PM, MURFING said:

no malware can infect my system just because an ad appeared,

Err, umm, well... 

 

 

The "good news" is that this likely is one of the infamous windows memory leaks...

 

You should try using ISLC, but I'm not 100% sure windows 11 is supported.

 

 

On 5/10/2026 at 7:56 PM, podkall said:

RAM and Windows can cache useless files of already closed programs, but it will be among the first files it will unload if system needs more RAM.

 

It does that in case you ever open such program again, the files that would go to RAM are already there.

Yeah, yeah, but nonetheless on my windows systems, the RAM always gradually decreases when not in active use down to 3-4 GB (if was 10 etc for example)

[podkall]

On 5/10/2026 at 7:40 PM, MURFING said:

But obviously, no malware can infect my system just because an ad appeared, especially if I didn’t click on it, right?

Unfun fact, there are ads that are malware, and you don't need to click, because the ads have to load somewhere...

 

2 hours ago, Mark Kaine said:

Yeah, yeah, but nonetheless on my windows systems, the RAM always gradually decreases when not in active use down to 3-4 GB (if was 10 etc for example)

My RAM stays at like 5GB, and I could try closing everything, but I doubt it will drop down to 5GB, a portion of RAM stays "used" even if the programs have finished their stuff..

[Mark Kaine]

On 5/12/2026 at 2:48 PM, podkall said:

Unfun fact, there are ads that are malware, and you don't need to click, because the ads have to load somewhere...

 

My RAM stays at like 5GB, and I could try closing everything, but I doubt it will drop down to 5GB, a portion of RAM stays "used" even if the programs have finished their stuff..

What's funny people always say "if you have more RAM windows will also use (cache) more ram" but I just upgraded from 16 to 32 and it's still using ~4GB most of the time ...

 

But I don't get "out of memory" warnings in Forza anymore, so...! 

[podkall]

17 hours ago, Mark Kaine said:

What's funny people always say "if you have more RAM windows will also use (cache) more ram" but I just upgraded from 16 to 32 and it's still using ~4GB most of the time ...

 

But I don't get "out of memory" warnings in Forza anymore, so...! 

I wouldn't say windows use more ram just because you have more ram, it would only do so if you launched enough apps to do that, but not everyone runs and closes 100 different programs

[Mark Kaine]

1 minute ago, podkall said:

I wouldn't say windows use more ram just because you have more ram, it would only do so if you launched enough apps to do that, but not everyone runs and closes 100 different programs

Well yeah that makes sense (and probably what's happening) but not what these people are saying! They say it just magically uses more ram!

 

 

[podkall]

12 minutes ago, Mark Kaine said:

Well yeah that makes sense (and probably what's happening) but not what these people are saying! They say it just magically uses more ram!

 

 

People say a lot of stuff, should I remind you about bottleneck calculators?