web shield slows me down

[JoseyWales]

hello all
for about 3 years when i run speed test from firefox i have never gotten my advertised speeds of 30/4, i have always blamed my my internet provider or comodo firewall for the slowdown but just recently i ran it from internet explorer and seen that my speeds were showing closer to what im supposed to be getting. this made me start to blame firefox when i googled this problem i eventually came across this http://forum.avast.com/index.php?topic=97312.0 so i temporarily disabled web shield and my speeds in firefox jumped back to normal. below are speedtest.net results i have ran test from others like my providers test, speakeasy and dsl reports test all with the same result

with web shield

disabled web shield


different location

with

without


also on youtube, dishonline, hbomax and others streaming was always choppy but with web shield disabled playback is smooth. i have 2 different computers with xp home and avast, both are having the same issue

[DavidR]

I see virtually no difference in mine when I run speedtest.net with the web shield on I get almost the theoretical maximum for my 40Mbps service  (account plan) at 37.40MB/s.

What is your firewall ?

[Theo Peterbroers]

It's a known issue with speedtest. It is inaccurate in the presence of webshield.

I prefer http://www.cfosspeed.de/speed-test/speed-test_en.htm to do this sort of test. They actually test by uploading / downloading reasonably sized files.

My Internet connection is specced at 2,5 Mbit upload, 50 Mbit download and I get (just tested)

(webshield on)
RX speed: 43897.69 Kbits/s
TX speed: 2460.89 Kbits/s
Response time: 64.4 ms
Test size: 55.2 Mbytes

(webshield off)
RX speed: 39590.21 Kbits/s
TX speed: 2458.64 Kbits/s
Response time: 80.1 ms
Test size: 51.8 Mbytes

Results are are good enough in both cases, in my opinion.

If you want a more in-depth analysis of your pc's access to the internet, try netalyzr.icsi.berkeley.edu/ 
They only give me this network bandwidth: Upload 2.4 Mbit/sec, Download 13 Mbit/sec. But hey, that's to the other side of the world.
The other tests they offer are really much more interesting

Best regards.

[DavidR]

Weird, for me the cfos speed test is way lower, be that with or without the web shield enabled.

A max of 21182.35 Kbits/s with the web shield enabled, but more strangely with the web shield disabled even slower, 19553.24 Kbits/s.

Though I have seen this on other speed tests were I get a faster download speed with the web shield enabled.

[polonus]

Have to agree with DavidR here, and would also have rather expected the opposite to be true. Do disallow a vital protection layer (the only one that alerted me over the last time) just for a mimimal speed gain is ludicrouus. Yes all scanning could slow you down and without protection an OS really, really starts to slow down after being infected. On the other hand all that is being blocked will slow less than when it has to be loaded. The issue here is there are other perimeters that count for the totall result and web shield could be only one of various variables or are you really observing with Fiddler what part of traffic over the wire is caused by web shield traffic?

polonus

[JoseyWales]

I see virtually no difference in mine when I run speedtest.net with the web shield on I get almost the theoretical maximum for my 40Mbps service  (account plan) at 37.40MB/s.

What is your firewall ?

^comodo firewall

i have been using avast since version 4.8 or 5 (cant really remember) and even after a fresh install of xp on both machines as little as 1 week ago my speeds have always been low using avast 5 - 7. there was no difference with me using just windows xp built in firewall or installing and running comodo my speeds were the same.  i have comodo set to allow avast.setup, avastsvc.exe and avastui.exe
i have now been experiencing with different antivirus programs and i hate to say it but avast is the only one that seems to slow me down even streaming youtube like sites is better with all the other free virus scanners. avast is the one i want to use i hate how heavy the others are.
if the slowdown only happens when running firefox with avast would it not be a problem between those two like i said with internet explorer and avast everything is fine streaming isnt choppy speed test are better but with firefox 3 - 12 and avast is my problem.

avast test below are with web shield enabled

chrome/avast/comodo - Click Image to Enlarge

FIREFOX/avast/comodo - Click Image to Enlarge

ie8/avast/comodo - Click Image to Enlarge


chrome/windows security essentials/comodo - Click Image to Enlarge

FIREFOX/windows security essentials/comodo - Click Image to Enlarge

ie8/windows security essentials/comodo - Click Image to Enlarge

startup programs

TrueTransparency
Avast
Comodo Firewall Pro

Services Running

avast! Antivirus
COM+ Event System
COMODO Firewall Pro Helper Service
DCOM Server Process Launcher
DHCP Client
Event Log
Fast User Switching Compatibily
HID Input Service
Network Connections
Plug and Play
Protected Storage
Remote Access Connectiion Manager
Remote Procedure Call (RPC)
Secondary Logon
Security Accounts Manager
Shell Hardware Detection
System Event Notification
Telephony
Terminal Services
Themes
Windows Audio
Windows Image Acquisition (WIA)
Windows Management Instrumentation
Wirless Zero Configuration
Workstation

[DavidR]

My thoughts on firewall might have been zone alarm as that has previously been featured in a slowdown, I believe due to its I/O or proxy handling.

Weird that this mainly presents itself with firefox and avast but not so much the other browsers as essentially the web shield works the same with the browsers and I use firefox exclusively on my systems (very rare I use IE8/XP or IE9/win7).

I don't believe that MSE has any web shield equivalent (I have never used it), filtering and scanning http traffic through a localhost proxy, so I wouldn't expect to see any impact.

What happens if you run the test using the safe mode firefox option from the Start, All Programs, Mozilla Firefox (Safe Mode) ?
If this works then I would be looking at a problematic firefox add-on and possibly a security based one.

[JoseyWales]

My thoughts on firewall might have been zone alarm as that has previously been featured in a slowdown, I believe due to its I/O or proxy handling.

Weird that this mainly presents itself with firefox and avast but not so much the other browsers as essentially the web shield works the same with the browsers and I use firefox exclusively on my systems (very rare I use IE8/XP or IE9/win7).

I don't believe that MSE has any web shield equivalent (I have never used it), filtering and scanning http traffic through a localhost proxy, so I wouldn't expect to see any impact.

What happens if you run the test using the safe mode firefox option from the Start, All Programs, Mozilla Firefox (Safe Mode) ?
If this works then I would be looking at a problematic firefox add-on and possibly a security based one.

for some reason firefox removed the safe mode in the start menu

In Firefox 4 the Start Menu shortcut for opening the Firefox SafeMode was removed and two new ways added
You can open the Firefox SafeMode by holding the Shft key when you use the Firefox desktop or Start menu shortcut.
Or use the Help menu item, click on Restart with Add-ons Disabled... while Firefox is running.

i get the same result running in safe mode -

thank you for your help

[DavidR]

Sorry that didn't reveal anything, this really will need to be looked at by someone with more in depth knowledge of network issues and hopefully a member of the avast team.