First, you could try "manage exceptions" and choose certain filepaths and folders for AVG to skip. It will speed up the scan but it can miss important areas if you don't choose the right areas to leave out.
I wouldn't do that because malware can hide anywhere, and even if its a folder you trust it still can be infected. Also the amount of speed time your loose is minimum, so I personally think that's not needed.
Second, disable the scheduled scan and try running the scans at night once a week. If you are handling large files when you're using it though you are still going to have to deal with Resident Shield kicking in.
I'm not exactly sure if disabling the schedule scan will increase the scan speed, but running a scan at night or at a time you do not need to use the computer is good, and if you run at night you can also tell AVG to shut-down your computer after the completion of the scan. I usually try to limit the amount of process/applications running in the background when running a scan.
Another suggestion I have is that during the scan, you can Disable
your internet connection and this should stop Resident Shield from popping up for me usually. Bottom line I would say you should avoid browsing the web and also do anything else just let the scan finish and then do what ever you want
Yes, you can always try a new Anti-virus program. I use AVG 8.0 too because I think its scan speed is fairly good. The amount of CPU it takes up is not a great amount for me.
Another aspect I like about AVG is it has different scan types. Near the bottom of AVG, you can set the scan to:Slow Scan, Automatic Scan or Fast Scan
takes the least amount of CPU usage, but it may take a while for the scan to complete, but at least you can do other things you need to accomplish while it is doing the scan.Automatic Scan
may vary so I can't say much about that.Fast Scan
will take most of your CPU usage and sometimes it even lags your computer because its trying to complete the scan as fast as possible, but again you can always run at a night time ;)
Those are just some of my suggestions/opinions.
Hope that helps