Do Virus Scanners Slow Down Your System?

Test System And Benchmarks

We begin by selecting the security software to test. We're curious to find out if Internet security suites might contain bloatware that could slow down a system more than a simple anti-virus program would, so we've included not only virus scanners, but also complete Internet security suites offered by noteworthy developers. This means we’re testing AVG Anti-Virus, AVG Internet Security, Kaspersky Anti-Virus, Kaspersky Internet Security, McAfee VirusScan Plus, McAfee Internet Security, Norton AntiVirus, Norton Internet Security, Trend Micro Titanium AntiVirus+, and Trend Micro Titanium Internet Security. [edit: we originally listed some obsolete versions of the AV software. The programs we actually tested were the newest available versions as of October, 2010]

Where benchmarks are concerned, we’ve assembled a suite of tests to exercise most aspects of PC performance, from gaming to office work. We’re testing raw application performance and also the time it takes for the system to respond to boot and to program launch requests. In order to do this, we’ve even developed some custom benchmarks, courtesy of our own Andrew Ku.

While we're running the benchmarks on an Athlon II X4 645, we'll be disabling two of the CPU cores for the majority of benchmarks. As a result, most of the benchmarks reflect the performance users can expect from a budget dual-core CPU. On page seven we run more benchmarks with only a single CPU core enabled, and also with all four CPU cores enabled, to see if the performance burden changes based on the number of execution cores available to the system.

With all this in mind, here are the particulars for our test system and benchmarks:

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Test System
MotherboardAsus M4A785TD-V EVO Socket AM3, AMD 785G, BIOS 0410
ProcessorAthlon II X4 645 3.1 GHz, Quad-Core CPUMultiplier set to 3.0 GHz*CPU RESTRICTED TO DUAL-CORE OPERATION FOR MAJORITY OF BENCHMARKS TO DEMONSTRATE BUDGET DUAL-CORE CPU PERFORMANCE*Single- and quad-cores enabled for CPU core comparison on page 7
CPU CoolerCooler Master Hyper TX3
MemoryCrucial DDR3-1333 Dual-Channel 2 x 2048 MB, 669 MHz, CAS 9-9-9-24-1T
GraphicsRadeon HD 5830 Reference 1 GB GDDR5, 800 MHz GPU, 1000 MHz Memory
Hard DriveWestern Digital Caviar Black 1000 GB 7200 RPM, 32 MB Cache SATA 3Gb/s
Software and Drivers
Operating SystemMicrosoft Windows 7 x64
DirectX VersionDirectX 11
Graphics DriversAMD Catalyst 10.9

And here's a list of the benchmarks:

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Benchmark Configuration
3D Games
CrysisPatch 1.2.1, DirectX 10, 64-bit executable, benchmark tool High Quality, No AA
Audio/Video Encoding
TMPGEnc 4.0 ExpressVersion: File: "Terminator 2" SE DVD (5 Minutes)Resolution: 720x576 (PAL) 16:9
Xvid 1.2.2Display encoding status = off
WinRAR 3.90Version x64 3.90, Dictionary = 4096 KB, Benchmark: THG-Workload (334 MB)
Synthetic Benchmarks
PCMark VantageVersion: x64, All Benchmarks
SiSoftware Sandra 2010Version 2010.1.16.11, CPU Test = CPU Arithmetic
  • theshonen8899
    Great article, thanks!
  • iam2thecrowe
    before i read the article, my guess is Norton is the slowest and most useless....
  • tony singh
    How can u forget Avira , it's so popular & so good .
  • alyoshka
    I guess the new ones are lighter than the earlier ones for some of them....
  • 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?
  • ruffopurititiwang
    This is the kind of article that keeps me coming back to Tom's! Kudos!
  • aznshinobi
    Avast please?
  • 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
  • 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?
  • tony singh
    @Fip - Because when dirty viruses do their job, you'll get a headache.