avast slowing down DSL connection

[JohnnyBob]

avast is slowing down my DSL connection.
 
I have the 3.0 ADSL service with AT&T which, under best conditions, produces a throughput speed of 2.526 with their system test. However I never get that with avast active. Turning on avast immediately lowers the throughput speed to 2.4, which is the best I can get with avast active & running. That's not too bad, but I'm getting speeds as low as 1.2 also, as follows...

When I first run their speedtest, typically I get a low speed, as low as 1.2. Then if I click their 'rerun' button, on successive tests the speed increases progressively. Typical might be 1.2, 1.7, 2.2, 2.3, 2.4, then it will usually stay at 2.3-2.4. That's with avast active.

If I turn off avast, instead of that scenario, I tend to get a fast throughput immediately, like 2.4-2.5. So avast seems clearly implicated in my DSL speed slowdowns. Fact is, my connection is sluggish, not snappy like it should be.

Trust me, I've been through the wringer with the AT&T tech people. They say everything is OK from their end, and I tend to believe them. They say it must be something at my end, and avast is the ONLY thing I've found that affects it. I've tried turning off my firewall, anti-malware software, and everything else. I've even reset my TCP/IP stack. The only thing I've found that affects the DSL speed is avast.

My question to this avast forum is - how can avast be involved? Do you think it's possibly the cause of these symptoms? Is there some kind of slow proxy server involved with avast that could be the cause? Or am I finally losing my marbles and going off my rocker?

[Lisandro]

How can avast be involved? Do you think it's possibly the cause of these symptoms?

I think WebShield scanning could be due to that. You must test if you want to reduce protection (given by WebShield) to improve performance. I won't do it if I were you

Is there some kind of slow proxy server involved with avast that could be the cause?

I don't think so. avast does not use remote proxy for scanning (just local, WebShield).

[benkar]

Im running Avast 4.7 Home Edition and having problems with the "On Access protection", it is slowing down http-acess very much on my Windows Vista Home-machine. (Only 2 weeks old hardware and 1 GB RAM)

I have two old machines with Win XP and W2k, also running Avast 4.7, and no problems with internet-speed.

My new PC runs Vista Home, and Avast 4.7 with the same settings as on the other machines, and a webpage that takes 1 secund to load in the old PCs, takes about 15-20 secunds to load from the new Vista-PC.

On the Vista-machine I have tried "everything", updates, nic-settings, different firewalls, but http-access with IE7 or Firefox is very slow, but if I turn of "On Access protection" it work/run OK conecting to internet/http-access.

Anybody any ideas about this, why is Avast On Access protection running/working so slow on Vista?

/B

[Lisandro]

My new PC runs Vista Home, and Avast 4.7 with the same settings as on the other machines, and a webpage that takes 1 secund to load in the old PCs, takes about 15-20 secunds to load from the new Vista-PC.

It's difficult to compare all other software installed. Are, at least, the browsers with the same configuration? (same extensions on firefox, for instance).

[benkar]

My new PC runs Vista Home, and Avast 4.7 with the same settings as on the other machines, and a webpage that takes 1 secund to load in the old PCs, takes about 15-20 secunds to load from the new Vista-PC.

It's difficult to compare all other software installed. Are, at least, the browsers with the same configuration? (same extensions on firefox, for instance).

I have tried with the same version of Firefox on all the PCs, and run ZoneAlarm on all PCs. On the Vista-PC have i tried to turn off all security, turn of disc-index, running Windows firewall instead of ZoneAlarm and so on.

I also tested the DSL (ASDL) -speed, get 2 MB download to all PCs when I run the test. If i run a ftp-program to down/up-load files I think that the speed is the same on all PCs. It is only at http-access to the internet with IE7 or Firefox the Vista PC is so slow, untill I turn of Avast On-Access scanner. I also feel that the problem is worst visiting websites with many small gif and jpg-pictures, the problem is less on sites with a few big pictures.

/B

[Lisandro]

Untill I turn of Avast On-Access scanner.

What happens if you disable only WebShield?
Which is your Standard Shield senstivity level? High or Normal?

[benkar]

Untill I turn of Avast On-Access scanner.

What happens if you disable only WebShield?
Which is your Standard Shield senstivity level? High or Normal?

No different in speed (http) if i disable only WebShield.

All Shields, including Standard Shield, have senstivity level Normal.

/B

[DavidR]

Although I doubt it will have any effect have you Terminated Network Shield ?

When you say disabled, web shield do you mean Terminate, the reason I say this is if you only pause it, the web shield proxy is still used although files aren't scanned ?

[Lisandro]

No different in speed (http) if i disable only WebShield.
All Shields, including Standard Shield, have senstivity level Normal.

I can't see avast involved in this scenario... maybe other software (a security software for instance) is interacting with avast...

[benkar]

Although I doubt it will have any effect have you Terminated Network Shield ?

When you say disabled, web shield do you mean Terminate, the reason I say this is if you only pause it, the web shield proxy is still used although files aren't scanned ?

Ok. now I have tried to really Terminate WEB Shield, not only pause, and with WEB Shield Terminated http-access to internet with the Vista-PC runs with same speed as the XP and W2K-PCs (but they have WEB Shield activated)

So, the problem is the WEB Shield, thinking of what to test next...  want to have the WEB Shield active...

/B

[DavidR]

No, that doesn't necessarily mean web shield is the problem, just that it is a contributory factor. If it were the problem then the XP and win2k systems would be the same. So if you applied the same logic, you could say that Vista is the problem as the web shield works on the other systems but not the Vista one.

We have to try and fine the true cause.

Can you terminate the Network Shield and enable the Web Shield and see if there is any difference ?

Can you state what your firewall is and what the additional security/anti-malware software
is (are they also on your other systems) ?

[benkar]

No, that doesn't necessarily mean web shield is the problem, just that it is a contributory factor. If it were the problem then the XP and win2k systems would be the same. So if you applied the same logic, you could say that Vista is the problem as the web shield works on the other systems but not the Vista one.

We have to try and fine the true cause.

Can you terminate the Network Shield and enable the Web Shield and see if there is any difference ?

Can you state what your firewall is and what the additional security/anti-malware software
is (are they also on your other systems) ?

Ok:

If I terminate the Network Shield and enable the Web Shield, same problem, http-access to internet is still slow.
If I terminate the Web Shield, and enable the Network Shield, http-access to internet is fast.

I use ZoneAlarm as Firewall, but have tried to uninstall ZoneAlarm and use Microsoft/Vista Firewall, same slow http-access to internet. I have also tried to use no Firewall at all, same slow http-access to internet.

I have no additional security/anti-malware software than Avast, and have tried to turn of all built in sceurity in IE7/Vista, and also tried using Firefox as webbrowser.

On the XP and W2k-PCs I have IE6 (and Firefox), Avast and Zonealarm.

/B

[Lisandro]

No, that doesn't necessarily mean web shield is the problem, just that it is a contributory factor.

Fully agree.

If I terminate the Network Shield and enable the Web Shield, same problem, http-access to internet is still slow.
If I terminate the Web Shield, and enable the Network Shield, http-access to internet is fast.

They're different providers and NetShield shouldn't be involved as WebShield on Internet scanning.

I use ZoneAlarm as Firewall, but have tried to uninstall ZoneAlarm and use Microsoft/Vista Firewall, same slow http-access to internet. I have also tried to use no Firewall at all, same slow http-access to internet.

How much the speed is decreased? Some decrease is 'normal' as scanning takes resources...

[benkar]

No, that doesn't necessarily mean web shield is the problem, just that it is a contributory factor.

Fully agree.

If I terminate the Network Shield and enable the Web Shield, same problem, http-access to internet is still slow.
If I terminate the Web Shield, and enable the Network Shield, http-access to internet is fast.

They're different providers and NetShield shouldn't be involved as WebShield on Internet scanning.

I use ZoneAlarm as Firewall, but have tried to uninstall ZoneAlarm and use Microsoft/Vista Firewall, same slow http-access to internet. I have also tried to use no Firewall at all, same slow http-access to internet.

How much the speed is decreased? Some decrease is 'normal' as scanning takes resources...

How much the speed is decreased?  For example, http://vtr.nu/

The startpage of http://vtr.nu/ , if I use the XP or W2K-PC, with "everything" turn on, Avast web shield an so on, loading the page takes about 1 second.

If I access that startpage with the Vista PC, with "everything" turn on, Avast web shield an so on, loading the page takes about 20 seconds.
If I turn of Avast web shield on the Vista PC, loading the same page takes about 1 second.

/B

[DavidR]

Strange I can access that on dial-up and it is loaded in under 10 seconds. Mind you I'm not using Vista.

Whilst this lag is going on, is the avast icon rotating ?
If not, check the Task Manager and see if there is a process talking up a high amount of CPU cycles and report your findings.

If so, perhaps if you enable Web Shield and also enable 'Show detailed info on performed actions,' this will show what is being scanned at the bottom of the screen.