How much does security software slow down your PC?

It is a pity that Webroot was not amongst those tested, there is no slow down on this computer at all, in fact I never konw it is scanning or anything.
 
3rd July 2015   By Ian Barker
 
One of the main complaints that people express about security software is that it harms the performance of their PC. But how much of an effect does it really have?
Independent testing organization AV-Comparatives has conducted a test of 20 leading security products for Windows to assess their impact. Tests were performed on a 64-bit Intel Core i5 machine with Windows 8.1.
 Performance was assessed on a number of tasks; file copying, archiving and unarchiving, installing and uninstalling applications, launching applications, and downloading files. These results were used to provide an AV-C score for each product. Researchers also ran the industry standard PC Mark 8 benchmark test and combined this with the AV-C results to come up with an overall impact score.
 
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