DavidR
6
I suspect that you wouldn’t see any appreciable difference in RAM more likely a difference in CPU, but since you already have the file system shield (FSS) in effective paranoid mode, that too is likely to be negligible.
There really is little benefit in scanning the other archives using the FSS. Archive (zip, rar, etc.) files are by their nature are inert, you need to extract the files and then you have to run them to be a threat. Long before that happens avast’s File System Shield should have scanned them and before an executable is run that is scanned.
The whole point of using the IM and P2p Shields is to intercept the traffic and scan it before anything is saved on your system. If malware is found then the connection for that item/element would be dropped, preventing it getting on your system. Prevention is a better course of action than cure, e.g. trying to remove something after it is on your system.