I have been a user of Avast for a number of years. I have been a big fan of 4.8 and just recently realized that v5 was released. I read on fileforum.betanews.com that the memory footprint of Avast has been reduced, so I decided to upgrade. I have a Lenovo T61 with a 2.4 GHz processor and 3 gigs of ram.
I have not seen a slowdown in loading websites really to be honest. I have seen a bit of a slowdown when doing things such as un-raring files. I have however noticed a BIG decrease in download speed from my newsgroup server. I would say that newsgroups have very consistent speeds and can be used to test connection speeds.
Anyhow, I noticed that my speeds have gone from 1-1.5 MB (yes, megaBYTES) per second to about half that. I have tried changing settings so that NNTP traffic wouldn't be scanned as vigorously (as I was able to do in 4.
. I was not able to fix the problem. I saw this forum and tried playing with the webshield. I tried turning webshield off, and didn't see any immediate effect (so I turned it back on). I then tried disabling the "Scan http traffic" option. No immediate effect, but in less than 5 min, my newsgroup download speed has returned to normal levels.
I had checked task manager to see if there was high CPU usage, and there wasn't anything there indicating this. Avast was using about 4-8% CPU. Total CPU usage was about 15%, so lots of room to go.
It seems the HTTP traffic scanning option does indeed slow things down. I'm using Chrome as my browser which is fast even on slow connections, so maybe that's why I didn't see a big change.
BTW, this is with Avast 5.0.462