Web shilds slows down Firefox, but not IE. What's the problem?

[Lars-Erik]

I have noticed that the loading/browsing speed is slower in Firefox.
And I tested with the most used norwegian speed test at http://speed.bredbandsguiden.no.

With Firefox (3, 11, 12, 13 and 14 versions) I get a download speed of 13 Mbps.
If I run the same test with IE8 I get 26 Mbps (much closer to my line speed).

On the Firefox newsgroup they asked me to try disabling things to lock down the source.

And when I disabled the "Web shield" in avast! I suddenly got full speed in Firefox too.

So the question is:  Why a 10 Mbps speed drop in Firefox with Web-shield on - but not in IE8?

Does IE8 bypass the Web shield (that is BAD) or is avast optimized for IE8 (and why)?

[lukor]

Hi,
do you have the same results on some other speed test site., e.g.: http://www.speedtest.net/


Thanks.
Lukas.

[Dch48]

What Windows version are you using? For me, there is no difference using either IE9 or Chrome in Win 7 64 bit but in XP Pro 32 bit, it's a different story. With the Web shield on in XP, I get right at 6mbs speed at Speedtest.net with both IE8 and Chrome. If I turn the Web Shield off, IE8 stays at the 6mbs but Chrome jumps up to 18 which is the speed I get in Win7 at all times.

[Nesivos]

I just tested the download speed with avast7! AIS, Firefox 12 B5, W8-CP,  It showed 5.77 MB vs my AT&T rated speed of 6.00 MB.  I think I can live with that.