I was not-at-all surprised by this report by The PC Spy called “What Really Slows Windows Down” that chronicles common applications and the performance impact they have in Windows. The top offender is Norton Internet Security 2006, with a whopping 46% boot delay and 20% cpu delay and 2369% File IO delay. The top thirteen (worst) are all antivirus packages. A developer I used to work with always said that the McAfee enterprise AntiVirus software was in itself a virus.
I’m turning off my realtime virus scanner. Permanently.
I haven’t had a legitimate virus blocked or alerted in this century. My email client, Outlook 2007, blocks executables. I can configure Winzip to scan archives before I extract them. I have a hardware router with NAT and stateful packet inspection. I use the OS firewall. I am clinically obsessive when it comes to patches and updates. I’ve got phishing blockers in FireFox (Google’s) and IE. I have backups of my important data. I’ll keep virus scan installed and run it Sunday nights, using the scheduler, but I am done letting software scan every single read and write on my system tying up resources. I’m tired of hearing from OSX people about how they don’t need antivirus installed.
Now, let me be clear, I do not recommend that anyone else do this unless you understand exactly what you are doing and where your vulnerabilities are.