Author Topic: what's wrong with the web shield? >>> serious bandwidth restriction  (Read 2499 times)

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there's been a thread here a little while ago, and I could hardly believe it. Now I just found another thread, on a French forum, mentioning that Avast Webshield was limiting the bandwidth, at least on flash sites like speedtest. I just checked and that's what I got with my connection...

without the web shield on speedtest >>> 27 Mb/s
with the web shield off >>> 63Mb/s

« Last Edit: September 15, 2010, 04:00:35 PM by Logos »

Offline Vlk

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Re: what's wrong with the web shield? >>> serious bandwidth restriction
« Reply #1 on: September 15, 2010, 02:21:15 AM »
It's true that with higher connection speeds, WebShield's effect is somewhat more noticeable. A proxy always has some performance implications, especially if it's a proxy like the WebShield which is scanning all the traffic.

The effect is very dependent on your CPU speed, actually. On a typical computer today, network speeds above 50mps will generally cause the WebShield to consume considerable CPU (and will possibly slow down the network throughput, too). You have to realize that we're doing a full scan on the whole stream, and that's not a cheap thing. :)

On the other hand, I find these tests somewhat superficial (= not necessarily related to the actual user experience). The reason for this is that WebShield detects large downloads and treats them differently (but the speed test tools usually use smaller downloads to do their job). That is, try downloading a file from a very fast server instead. I assume that the WebShield effect won't be noticeable in this case (neither download speed wise nor CPU usage wise). And in case of small downloads, the raw download speed isn't that important as many other things come into play (such as the latencies caused by connection establishment etc.)

BTW try disabling the Stream scan feature in the WebShield settings. This will make the test complete faster (but of course, is not a recommended setting as it does have security implications).

« Last Edit: September 15, 2010, 02:24:11 AM by Vlk »
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Re: what's wrong with the web shield? >>> serious bandwidth restriction
« Reply #2 on: September 15, 2010, 02:41:52 AM »
hey thanks for the feedback ;)

 I could actually hear the CPU fan become just really loud during the tests, I didn't check the load nor the process involved but this seems to confirm your description. I'll try different tests again tomorrow with web shield on and off (as well as stream scan off).
« Last Edit: September 15, 2010, 02:43:37 AM by Logos »