Sign in with
Sign up | Sign in

Single-, Dual-, And Quad-Core Benchmarks

Do Virus Scanners Slow Down Your System?
By

We think it’s important to address one of the variables missing from our previous tests, and that is hardware. As we’ve seen up until this point, most applications don’t seem to show a notable difference in performance, regardless of whether security software is installed or not. But all of the tests have also been run on a dual-core CPU, too. Will the results change on a single- or quad-core processor?

We would expect the raw performance to drop slightly in multithreaded applications. But we're curious about the effect security software has on single-core performance, too. While we don’t have time to run the entire benchmark suite for different processor setups, we run all three CPU options with AVG AntiVirus 9, AVG Internet Security 9, and without any security software installed for a quick test:

While the number of available execution cores can certainly affect the raw results, when it comes to comparing performance on the basis of available compute resources, the only metric that shows a significant performance drop associated with a single-core processor running security software is the time it takes to load Internet pages on the first run. Aside from that, security software doesn’t seem to have an adverse affect on single-core PCs. This is a surprising result, as we expected security software to take advantage of threading. It’s possible that our test scenarios don’t give the software an ideal opportunity to do so, but it’s a surprising result nonetheless.

Ask a Category Expert

Create a new thread in the Reviews comments forum about this subject

Example: Notebook, Android, SSD hard drive

Display all 239 comments.
This thread is closed for comments
Top Comments
  • 38 Hide
    Hupiscratch , November 30, 2010 6:44 AM
    I think Microsoft Security Essentials should be included if possible and there is a situation that I think it is greatly affected by anti-virus software: Windows start-up.
  • 32 Hide
    aznshinobi , November 30, 2010 5:48 AM
    Avast please?
  • 24 Hide
    apache_lives , November 30, 2010 6:31 AM
    this is tested on a fresh install - the average system has a ~2 year old install and fragmentation and lower end hdd's, combind with a crapload of other software trying to startup - no really a real world benchmark.
Other Comments
  • 5 Hide
    theshonen8899 , November 30, 2010 5:30 AM
    Great article, thanks!
  • 24 Hide
    iam2thecrowe , November 30, 2010 5:31 AM
    before i read the article, my guess is Norton is the slowest and most useless....
  • 24 Hide
    tony singh , November 30, 2010 5:41 AM
    How can u forget Avira , it's so popular & so good .
  • -3 Hide
    alyoshka , November 30, 2010 5:43 AM
    I guess the new ones are lighter than the earlier ones for some of them....
  • 4 Hide
    ruffopurititiwang , November 30, 2010 5:45 AM
    This is the kind of article that keeps me coming back to Tom's! Kudos!
  • 32 Hide
    aznshinobi , November 30, 2010 5:48 AM
    Avast please?
  • 4 Hide
    micr0be , November 30, 2010 5:49 AM
    talk about heavy modifications on the new set of AVs compared to the older ones ... my surprise is norton which i was expecting to cripple the system to a halt .... very nice article btw
  • 2 Hide
    tony singh , November 30, 2010 6:00 AM
    @Fip - Because when dirty viruses do their job, you'll get a headache.
  • 13 Hide
    iam2thecrowe , November 30, 2010 6:05 AM
    iam2thecrowebefore i read the article, my guess is Norton is the slowest and most useless....

    well i am really surprised
  • 2 Hide
    takeapieandrun , November 30, 2010 6:24 AM
    iam2thecrowewell i am really surprised

    I get Norton Security Suite free with Comcast. I was kind of bummed when I found out that's all they have available, but so far its been good to me. I haven't noticed any adverse effects, maybe startup is s little slower.
  • 24 Hide
    apache_lives , November 30, 2010 6:31 AM
    this is tested on a fresh install - the average system has a ~2 year old install and fragmentation and lower end hdd's, combind with a crapload of other software trying to startup - no really a real world benchmark.
  • 9 Hide
    Anonymous , November 30, 2010 6:31 AM
    it would have been useful to see a difference in the benchmarks using different HDDs like the 5400 RPM laptop ones, 7200 RPM and SSDs, that would have made a difference
  • 4 Hide
    Anonymous , November 30, 2010 6:43 AM
    Well the biggest slowdown you will experience with antivirus software is when you open a folder full of exe files and explorer tries to show all the icons of the executables. There is a very noticeable slowdown in that case.
    Also i would have liked a startup benchmark, because the antivirus also slowdowns somewhat the startup process.
  • 38 Hide
    Hupiscratch , November 30, 2010 6:44 AM
    I think Microsoft Security Essentials should be included if possible and there is a situation that I think it is greatly affected by anti-virus software: Windows start-up.
  • 5 Hide
    cjl , November 30, 2010 6:58 AM
    iam2thecrowewell i am really surprised

    Norton has VASTLY improved compared to what it used to be. I use Norton 360, and I have to say that it has been a great product.
  • -7 Hide
    Anonymous , November 30, 2010 7:04 AM
    2 ddragoonss
    thanks,
    AV is far from 100% protection, and could bring new problems (recently ESET NOD Smart Security causes problem with internet connection due to connection inspection / filtering ... ) For IT Pro is risk to get a virus very low, and if get one - few hours to get it out is worh instead of years of boring my pc with AV software
Display more comments