Which Antivirus Software Has the Least System Impact?

Which antivirus software has the least system impact?

It's true: Antivirus programs can deadening your computer, sometimes by quite a lot.

Withal nosotros've institute several antivirus programs with system slowdowns and so small that you'll never detect them unless you're doing something processor-intensive, such every bit playing a high-end game or rendering video footage.

The lightest paid antivirus program we tested is ESET Smart Security Premium, which slowed our test laptop by almost 12% during active scans. ESET is also ane of our picks for best antivirus overall.

The lightest complimentary antivirus programme was Kaspersky Security Cloud Free, whose system impact ranged from -i% in the groundwork (it actually sped the system upward a bit) to 6% during a full scan.

	Passive slowdown	Full-scan slowdown	Quick-scan slowdown
Avast Free Antivirus	4.4%	29.ii%	53.two%
AVG AntiVirus Free	5.three%	12.8%	25.6%
Bitdefender Antivirus Free Edition	2.2%	29.2%	N/A
Bitdefender Full Security	19.2%	32.seven%	30.ane%
ESET Smart Security Premium	two.0%	eleven.8%	Due north/A
Kaspersky Security Cloud Free	-0.9%	v.eight%	one.2%
Kaspersky Total Security	eleven.8%	26.five%	21.6%
McAfee Total Protection	8.9%	96%	38.6%
Microsoft Windows Defender	North/A	20.three%	12.8%
Trend Micro Maximum Security	3.9%	56.ix%	35.3%

How nosotros test AV software performance bear on

We tested six paid Windows antivirus programs in the summer and autumn of 2020 on a Lenovo ThinkPad T470 notebook reckoner. We tested five free Windows antivirus programs on an Asus X555LA notebook in the spring of 2019, and a sixth gratis Windows plan, Kaspersky Security Deject Free, in the autumn of 2019.

We used our abode-grown Excel benchmark test, which measures how long it takes the CPU to friction match 20,000 names with 20,000 addresses on a spreadsheet, to gauge arrangement impact. For Kaspersky Security Cloud Free, nosotros used a previous version of the aforementioned test that ran on OpenOffice.

We measured system speed before any 3rd-party antivirus program was installed; after an antivirus program was installed, only not during whatsoever agile scans; during a full scan; and during a quick scan. Each test was run 3 times for each programme, and the results averaged.

The numbers recorded were the completion times of the name-and-address matching tasks. Slowdowns were calculated using the pre-installation completion times every bit baselines and calculating the percentages by which each task increased the amount of time needed to consummate the matching task. Baselines were taken separately for each programme's set up of tests.

The results

Amid paid antivirus programs, ESET was non the fastest in all iii categories that we measured: passive organization impact, full-scan system impact and quick-scan system impact.

That may exist because ESET doesn't have a quick-scan selection. The lightest quick-scan touch among paid programs was held by Kaspersky Total Security at 22%, a percentage that was near twice as much as ESET's full-browse impact. Kaspersky did have the 2nd-lightest full-scan bear upon in the bunch, withal.

Kaspersky Security Cloud Complimentary was the undisputed winner in the free categories, beating all rivals in passive, full-scan and quick-scan impacts. It actually sped up the organisation a fleck later installation, indicating that it may be more efficient that the congenital-in Microsoft Windows Defender, which runs by default but deactivates itself if a third-political party antivirus plan is installed.

Kaspersky Security Cloud Free's total-scan organization impact was a barely noticeable six%; its quick-browse impact was a barely measurable 1%.

The runners-up

Most other programs were less consequent in their rankings. For case, McAfee Total Protection had a relatively lite background touch, slowing down the Lenovo laptop by only ix% after installation. But McAfee'southward full browse hit our test laptop similar a ton of bricks, slowing it downwards by 96%.

You'd probably detect that full-scan slowdown even if you were just checking email. You wouldn't find ESET'southward 12% hit unless you were intensively using the processor already.

Besides, Avast Free Antivirus (4.4%) had less of a background bear on than its sibling AVG AntiVirus Gratis, (five.two%). But Avast'southward full-scan slowdown was the heaviest at 53%, while AVG's was less than half that at 25%.

It'south hard to determine a 2d place among the paid programs. Two of them, Bitdefender Total Security and Kaspersky Total Security, had relatively high mail-installation background system impacts, of 19% and 12%, respectively, yet traded that for fairly light impacts — 33% and 26% — during system scans.

On the other end of the scale were McAfee Full Protection and Trend Micro Maximum Security, which had background impacts in the unmarried digits, all the same full-scan slowdowns of 96% and 57%, respectively.

In other words, you'd be trading a small amount of permanent background noise for huge slowdowns during full scans, which you could schedule to happen simply at night while the computer is idling.

Establishing the second-place finisher among the costless programs is even more muddled. Microsoft Defender Antivirus, aka Windows Defender, can't really be measured for background organisation impact because it'southward built right into Windows 8.1 and Windows 10. Just it had a very respectable total-scan slowdown of 20% and a quick-scan one of thirteen%.

Meanwhile, Bitdefender Antivirus Free Edition doesn't accept a quick-browse option. Its background touch is simply ii%, the best after Kaspersky. But its total-scan slowdown is 29%, tied with Avast Free Antivirus for concluding.

It is clear that Avast is in terminal place in the free bunch. Not only was it tied with Bitdefender Complimentary for the largest total-browse slowdown, just information technology had the largest background impact (after AVG AntiVirus Free) and a whopping quick-browse slowdown of 53%, the nearly among all the free programs.

How antivirus programs are marketed

Most antivirus brands offer three or 4 different paid Windows programs, all sharing the aforementioned basic protections but adding a few more than extra features with each increment in price.

For example, Bitdefender offers Bitdefender Antivirus Plus, Bitdefender Internet Security and Bitdefender Full Security, and each costs about $twenty more per year than the previous one.

But only the last has all the bells and whistles that Bitdefender offers, such every bit a password manager, webcam protection, parental controls or a system optimizer. Meanwhile, Bitdefender Antivirus Free Edition uses the same malware-detection engine as its paid siblings, just with far fewer options and extra features.

When deciding which antivirus program to buy (or download for free), evaluate which one has the features you need. For more on this, check out our guide on how to choose antivirus software.

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Paul Wagenseil is a senior editor at Tom's Guide focused on security and privacy. He has likewise been a dishwasher, fry cook, long-booty driver, lawmaking monkey and video editor. He's been rooting around in the information-security space for more than xv years at FoxNews.com, SecurityNewsDaily, TechNewsDaily and Tom'southward Guide, has presented talks at the ShmooCon, DerbyCon and BSides Las Vegas hacker conferences, shown up in random TV news spots and even moderated a panel word at the CEDIA home-technology conference. You tin follow his rants on Twitter at @snd_wagenseil.