A memory mystery involving Avast: can you solve it?

I have a mystery involving Avast and my memory and could use some help solving it. I’m running Vista 64bit. After Avast runs a full scan, the amount of memory “in use” (not superfetch) jumps from ~ 1.5 GB to ~ 2.8 GB and stays at roughly 2.8 GB until I reboot. Thus, for some reason the running of an Avast scan is causing Avast to use about 1.3 GB of memory and then keep that memory in use even though the scan is complete and program closed. While I do have more than enough memory (8 GB) such that this doesn’t cause problems, it seems very odd to me that after the scan is complete my memory “in use” would show to be 1.3 GB higher than before the scan. I’ve tested this a few times and it’s the same things…always caused by the AV scan (both manually initiated as well as scheduled scans). Any ideas on what’s happening and why Avast is not releasing that memory or for that matter, using that much memory for a scan. Very odd to me. I’ll post some screen shots of Task Manager showing memory usuage and programs in use both before and after. (Edit: My screen shot file sizes are too large to allow uploading).

Hi, are you saving your screenshots as png,jpg ? Those should’nt be too large to post.
I have vista x64 and avast and would like to see screenshots.

I saved them to a MS Word document.

Hi,just use the snipping tool and save as jpeg or png and they should be small enough. Hope this helps, tim

Thanks. I’ll have to try that later today when I get home to Vista PC. At my work PC right now and it is using XP and I don’t see where there’s a snipping tool.

Crop the image to the relevant parts as suggested, .gif format will give you the smallest file size and for web use is fine for quality.

There isn’t a snipping tool as such, you can use the Alt key + the Print Screen key together that copies the active window into the clipboard. You then need an image/graphics program MS Paint would do to paste the contents from the clipboard. Here you can crop if needed (but the Alt+Prt Scr should keep it to a reasonable size) then you need to save it as an image file.

Hi,in Vista, start>all programs>accessories>snipping tool. Hope this helps,tim

Thanks. Here you guys go.

These first two are the Pre-scan task manager listings. I had to divide into two because of the length of the list.

These two are the Task Manager listings after an Avast Scan with the higher memory being retained. Again, two parts due to the length of the list.

Any thoughts?

As a further update to this, I rebooted my computer, ran a scan and the memory again stayed up at about 2.8 GB even though the scan was done and closed. Then, later that night my scheduled scan ran (had forgot about that) and the next morning I noticed my memory “in use” was about 3.2 gb even though Avast had finished the scan and closed. Why is Avast using so much memory and keeping it “in use” even after closing?

Can you please point to the information in the screen shots you posted that indicates avast is using this memory.

The task manager shows ashServ.exe using 27Mb which comes nowhere near the Gb of memory you report avast to be using.

Can you post a screen shot that shows the basic information on your memory use from the performance tab in the task manager? I ask since (though I am not a Vista user) I have read that Vista is not very effective at using the amount of physical memory you report being installed.

So the 18% and 35% are percentages of what?

Previously I didn’t even check the images as they are huge at 1680X1050, you don’t have to view the task manager at full screen as there is a huge amount of white space with nothing on it…

You can also click on the column headings to order the list by A-Z on that column clicking it again reverses the order so you could get away with a much smaller image, see image.

I have to agree with Alan, none of the avast processes after the scan are in anyway considered excessive, and seeing the percentage of physical memory used as 35% I somehow doubt you have 9.1GB of physical ram as that would be what 3.2GB would represent (35%) if you had 9.1GB of physical RAM. So something just doesn’t stack up or should that be add up.
How much physical RAM do you have installed ?

Just have a look at my task manager image (XP Pro) and look at the ash/asw entries and I haven’t done any scan and also look at the real hogs explorer and firefox.

So I too don’t know where you are getting these figures of 2.8 and 3.2 GB from, but according to your own images, the combined total for avast process aren’t responsible for these figures.

Alan and David - Thank you for your replies. Here are some details to clarify the information:

My system has a little bit over 8 GB of memory (I think roughly 8.2 GB) (running 64 bit Vista).

The memory amounts I quoted were from a gadget monitor on my Side Bar that tells me the specific amount of memory in use, amount available and CPU activity for each of the 4 cores. I rounded the numbers since the exact amount didn’t seem important.

18% and 35% come from Task Manager and are the percentage of memory; it confirms what the side bar gadget is reporting. 18% of 8.2 GB is 1.47 or about 1.5 GB. 35% of 8.2 GB is 2.87 GB

The screen shots of Task Manager were done before and after the first scan by Avast. The 3.2 GB number in my updated post of October 6th is after a second scan by Avast was done. I did not do a screen shot of Task Manager after this but the percentage would have presumably corresponded.

The bottom line is that it is a mystery to me as to what is happening with the memory but it revolves around the single issue of an Avast scan occurring. I have repeated this several times…all with the same results. For instance, I reboot my system. Let everything load and stablize for bit of time so all background start-up processes are done running. Memory is showing at roughly 1.5 GB in use. I initiate a scan by Avast and after it’s done the memory holds at roughly 2.8 Gb in use even though the scan is done and the Avast user interface is closed. If I run another scan after that, more memory is used and left in use even though the scan is done and closed. In my example above, the memory in use went up to 3.2 GB. The only thing that I’m aware that has ran is Avast. That’s the common thread in this issue. I’m not sure where the memory goes but Avast is causing something to happen in Windows so that some elements or process in Windows is holding onto that memory.

Well in windows even 64bit OS versions of it manage the memory usage and the relinquishment of such.

Whilst RAM is there to be used or you would have to constantly keep going to the HDD swapfile, etc. which would be worse (IMHO).

So I guess it would depend on how you have the OS memory management set, in XP Pro 32bt you can set how memory is used for system or application performance, etc. I don’t know if there is a corresponding setting and if it would really make much difference.

However, none of that detracts from where the image showing the 35% memory usage, the avast processes are a drop in that ocean, so you will have to see if there are any better tools to determine exactly what is using the RAM.

Hi, isn’t the extra memory consumed by the file cache? That would be very wise thing from Vista to do.

Sadly, when only 35% of you memory is in use, you are wasting 65% of you ram, which is in your case about 5.2 GB. What a waste!!! I wish my OS would be able to use ALL the memory I buy (at least for file cache), since after all I have bought it for the OS, not just as a filler in the empty space of my computer box.

No. While I agree with the concept of what your saying…if you have open memory, use it. In fact, Vista does that…it’s the Superfetch feature, which over time watches what programs you use the most and stores key start-up parts in the unsued memory. Caches those programs in the memory not being used so when you call up that program it loads faster than it would if it had to pull it from the harddrive. If, for some reason, a program you open needs more available memory to run, Vista flushes part of the cached memory to give you more on the front end.

The situation I have that forms the basis of this thread is not the Superfetch or cached memory but the fact that when Avast is done scanning its not releasing all the memory it used even though it’s done and closed. It’s the memory that’s in actual use by the system that I’m concerned about, and when Avast runs a scan I can see my memory in use jump up more than 1 gb (caused by the Avast scan because that’s the only thing I can see that is occuring at that moment, and I have tried it multiple times at different times of the day with the same results) and when Avast closes, that memory usuage does not go down as it should. It just hangs in there. Not a big deal at all given the amount of RAM I have installed but it’s clearly not functioning as it should. When a program closes, the memory it consumed and was using should be released. Imagine if all programs acted like what I’m seeing with the Avast scan and memory, eventually the failure to release that memory would cause more and more memory to be used up as you opened new programs throughout the day to the point eventually that you have no more memory and are receiving insufficient memory errors despite actually having 8 gb of memory and currently running programs needing only a fraction of it.

In any event, I’m still perplexed by this behavior between Avast and Vista 64 bit.

Hmm, aha, however, you should be able to see the process which appears to be consuming the memory in the task list? Are you? From the screenshot you’ve posted it does not seem to be ashserv.exe – which is the “Avast! antivirus” service responsible for scanning and possibly eating memory for avast.

Agreed. That’s what is making this whole thing a mystery to me. I can’t see in the processes where Avast is still assigned that amount of memory but the whole things occurs only when and after running an Avast scan. Very odd. My guess is that Avast uses some windows service in running the scan and that windows service is hanging onto that memory. But, if that guess is correct, I can’t figure out which one.

I still don’t know how then did you determine the amount of memory taken? Just from the number bellow ? (18% versus 35%) ? How do you know what exactly is counted into this number, file cache, prefetch, etc.