Kaspersky Security Cloud Free was the undisputed winner in the free categories, beating all rivals in passive, full-scan and quick-scan impacts. Kaspersky did have the second-lightest full-scan impact in the bunch, however. The lightest quick-scan impact among paid programs was held by Kaspersky Total Security at 22%, a percentage that was nearly twice as much as ESET's full-scan impact. That may be because ESET doesn't have a quick-scan option. The resultsĪmong paid antivirus programs, ESET was not the fastest in all three categories that we measured: passive system impact, full-scan system impact and quick-scan system impact. Baselines were taken separately for each program's set of tests. Slowdowns were calculated using the pre-installation completion times as baselines and calculating the percentages by which each task increased the amount of time needed to complete the matching task. The numbers recorded were the completion times of the name-and-address matching tasks.

Each test was run three times for each program, and the results averaged. We measured system speed before any third-party antivirus program was installed after an antivirus program was installed, but not during any active scans during a full scan and during a quick scan. For Kaspersky Security Cloud Free, we used a previous version of the same test that ran on OpenOffice. We used our home-grown Excel benchmark test, which measures how long it takes the CPU to match 20,000 names with 20,000 addresses on a spreadsheet, to gauge system impact.

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