Avast and Network Copy Performance?

[rbeane]

I noticed my copy performance across my wireless network seemed slowed, so I did some informal tests.  I am copying between 2 vista laptops both wireless(54G).  I am copying pictures(approx 4.5MB/file) using a copy and paste from directory to directory. 
With Avast standard shield up on both computers or one of the two computers(it didn't matter either way) the files copy at approx. 550KB/Sec according to the details of the copy dialog in vista.
With avast standard shield paused on both computers the files copy at approx. 1.1MB/sec or double the speed.

I also noticed that when the standard shield is on, it scans the source file on the remote computer then scans the same file on the target computer based on the On-Access dialog Last Scanned field. 

Is it normal for copy performance to be cut in half for virus scanning?

[rbeane]

bump

[rbeane]

Anyone having any ideas or maybe confirm the findings?

[DavidR]

Sorry I don't use Vista but there are numerous reports of how slow it is transferring files, I don't know if you have SP1 but that was supposed to improve the slow coping of files.

[rbeane]

Sorry I don't use Vista but there are numerous reports of how slow it is transferring files, I don't know if you have SP1 but that was supposed to improve the slow coping of files.

Thanks for the response...I was beginning to wonder if anyone would respond. 

As for Vista, this doesn't appear to be a vista specific issue.  The speed doubles by pausing the Standard Shield.  If it was vista it would be the same on or off.  Just for information, it is SP1. Avast seems to be checking the file twice.  First when reading it from the source computer then when putting it on the target computer.  I don't think Avast should be cutting copy performance in half.  Maybe someone can confirm my findings or a developer can explain the reasoning behind it.

While this may be a avast on vista, it really doesn't appear to be a Vista issue.

[DavidR]

Well I would have though that the source computer might scan the file being accessed, though I don't know this for certain (I don't have a network to test it) and then it would be scanned on the destination system as that would be a creation of a new file (auto scan by standard shield, depending on the file type).

Have you made any changes to the avast settings ?

You don't mention what sensitivity you have set on the Standard Shield, Normal is the default, if set to high that would increase the number of files scanned.

If this were truly halving cutting and copying performance in half, I would expect to see many, many topics on this, but I just don't see it in the forums and you could say I'm fairly active in the forums. This may possible be why there has been a lack of a response as people aren't experiencing the same problem as you.

What other seciruty software do you have installed, firewall, anti-spyware, etc. ?

[rbeane]

Just so I am not confusing the issue, the Target computer is scanning the file on the source and then again on the Target computer.  Settings are normal and no other security software installed(other than MS defender which is standard in vista and vista's firewall).

I would agree with the lack of threads on this which is why I was hoping to have someone confirm my findings.  But it doesn't seem that as many run vista vs. xp on this forum.  Then you would need to have a multiple computers on a network and be copying large files.

If we can confirm my findings, then we can rule out my systems specifically.  Settings are all default.

[DavidR]

There are many on the forums that are using avast and vista on the forums, though how many are running them on a network is probably much less.

What version of avast are you using, the latest is 4.8.1229, there have been a couple of program updates recently, which might include vista improvements, check this page(http://www.avast.com/eng/avast-4-home_pro-revision-history.html).

Other than that I'm at a loss as to what else to suggest, hopefully one of the Alwil team will pick up on this topic.

[rbeane]

Thanks for the update information.  The informal test was done with 4.8.1201, but I have since updated to 1229. I looked at the updates for the versions, but it doesn't appear to have addressed anything like this.  Thanks for all your help.  I can test again, but hopefully someone will see this thread and make some more suggestions.

[DavidR]

You're welcome, good luck.

[olddog]

I don't have Vista, nor a wireless network, but I do have three XP machines on an ethernet (hard wire) network, via a router. One of the PC's is XP-Home SP2, one is XP-Home SP3, one is XP-Pro SP3.

I have Zone Alarm firewall on all of them primarily to look after outgoing - the firewall in the router is the primary for incoming. All three have Avast 4.8.1229, with the Standard shield set to High. All three have Spybot 1.6 fully immunised. Two of the three have Teatimer (the latest beta version) active.

I don't see the double scan you are talking about. Regardless of which PC the copy/paste is initiated from, the scan appears to be only being carried out by Avast on the machine the file is being copied to.

Does it slow down a file transfer - yes, but certainly not to an unacceptable degree. It's a bit like pouring tea from the teapot to the cup - if you use a fine wire strainer, it is slower and so takes longer, but the advantage is you don't have to put up with tea leaves in your cup.

[rbeane]

My scan is also only carried out on the machine that the file is being copied to.  But it is scanned by that machine twice as I said above.   Once when it is read from the source computer and once when it is copied to the target which is all happening on the target computer.  Did you try to copy large files so that you could see the last scanned file for long enough given that you are using a wired connection?  How fast was it with Avast on and avast off?  It could be a Vista/Avast issue but we can't tell without hard numbers from another Vista machine and/or your XP machines.  Maybe someone with Avast and vista could test it.  While I understand your tea comments, 550KB/sec vs. 1.1MB/sec is a lot of tea time.

[olddog]

Stuck@home,

My apologies, I should have posted some details to allow comparison.

I used a 70.984MB .bmp file for the test, copying the file from an Asus portable with a 1.66GHz T1300 Intel Solo processor running XP-Home SP2, via the router to a 2.4GHz Intel Core 2 Duo desktop PC running XP-Home SP3. Both have all MS updates. Both the portable and the desktop have 1GB memory, and both have Zone Alarm firewall version 7.0.483.000 software active. Both have Avast 4.8.1229, with the Standard shields set to high.

The first copy/paste was made with all the avast shields shut down on the desktop PC (right clicked the "a" ball, clicked Stop On Access Protection). Avast was left fully active on the portable. The time from the paste instruction to completion of the copy was 9.11 seconds.

The file was then deleted from the desktop PC, Avast was reactivated and both computers were rebooted. The time from the paste instruction to completion of the copy with Avast active on both PC's was 9.14 seconds. So you can see why I said the amount of slowdown was not concerning me.

Perhaps this is Vista related - unfortunatey I don't have a Vista system to test, so I have to leave that to someone else. 

[rbeane]

Thanks for the info.  Your time difference IS negligible. Maybe this is a Vista + Avast issue, which would explain why this may not be a common problem on this forum.

While some may have Vista, many may not be copying large files from network computers.  I am interested in getting a Home Server, but I am concerned about performance of file access and movement based on my test.  Hopefully someone can confirm my Vista findings and/or I can determine that it is a setting on my computer.  Hopefully we get some more info from other users.

[olddog]

Stuck@home,

I have realised that on the copy being scanned, I should have timed to the point where the "a" ball ceased to spin at the end of the copy, rather that at the "windows" completion of the copy itself, so to make this correction for the sake of accuracy, the revised time with Avast active is 11.26 seconds. Still not the sort of difference you are experiencing, and again, I still find no evidence of the dual scan.

Hope we can get some other to run a similar test.