Skip to main content

Do Virus Scanners Slow Down Your System?

Single-, Dual-, And Quad-Core Benchmarks

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.

  • theshonen8899
    Great article, thanks!
    Reply
  • iam2thecrowe
    before i read the article, my guess is Norton is the slowest and most useless....
    Reply
  • tony singh
    How can u forget Avira , it's so popular & so good .
    Reply
  • alyoshka
    I guess the new ones are lighter than the earlier ones for some of them....
    Reply
  • well from my point of view - antivirus scanner do application loading to take a much longer time and this was proven by your tests.

    I think that AV software has no place into todays operating systems except for inexperincied users. I'm investing money to fast SSD disc to improve performace, why the hell intstall AV software to push performance back?
    Reply
  • ruffopurititiwang
    This is the kind of article that keeps me coming back to Tom's! Kudos!
    Reply
  • aznshinobi
    Avast please?
    Reply
  • micr0be
    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
    Reply
  • The test rig's CPU looks funny to me.

    Athlon II X4 645
    3.5 GHz, Quad-Core, 6 MB L3 Cache

    Isn't that a Phenom?
    Reply
  • tony singh
    @Fip - Because when dirty viruses do their job, you'll get a headache.
    Reply