Do antivirus scans really need to brick your computer?

Posted at 19:10 on 05 December 2008

Pretty much every antivirus software package that I have ever used has a really annoying flaw. Whenever it launches into a full system scan, it slows your computer down so much that it hardly even responds to your keyboard and mouse. Given that a typical PC has up to half a million files knocking around on the hard disk, such a scan takes a good couple of hours at least.

It seems that when they perform a scan, they process the files back to back, which results in a lot of churning of your hard disk as the heads continually seek all over the place to find the next one. The fact that they're both processor intensive (with fairly complex heuristics and pattern matching algorithms) and hard disk intensive means that during this time, they effectively brick your PC for a good two hours or so.

I'd have thought it would be fairly easy for them to fix this, by introducing a pause between each file (or each chunk of a file, for larger files) to give your computer a chance to respond to user input in a timely fashion. They could go in to a fast mode if you were running a screensaver, but while you're actually trying to get some work done, you really want them to ease off the gas.

Unfortunately, I've not yet come across any antivirus programs that do this. Why not?