Monday, 22 December 2014

Tested: The Lightest Free Antivirus (To Boot or get the Boot)

I have the weakest netbook laptop available.  I need an antivirus that doesn’t take forever to start and shut down my machine.  And I don’t want my system to be all gummed up and frozen.  In addition, my friend has an old XP and asked for recommendations for protection.  MSE won’t run on his system anymore and while some still offer support for XP, they are too heavy for it.  The professional labs did some testing for performance, but their recommendations don’t even approach reality when run on my weak, weak system.  And each seems to have a different criteria for `running lightly’.  My criterion is boot speed, physical memory used, and the percent of the CPU utilized.  My tests were informal and for personal reasons, I now submit to help others.  Testing time was beginning of 2014.

Test machine:  Windows 7 starter running on an Intel atom (N450, single core) processor.   1 Gb RAM.  160 Gb HDD.  A base system restore point was created.  Wise 360 was the boot analyzer.  Process Hacker provided additional information.  Antivirus was installed, tested, uninstalled via Wise Uninstaller, and then system restored for the next program.

I like to have phishing protection and most free antivirus’ do not offer full protection.  If an antivirus solution did not have its own built in protection, I ran Mcafee Site Advisor.  AVG and Panda each have their own proprietary equivalent protection:  So with each of these I ran their software and deleted Site Advisor.  (as stated, testing was for personal, not scientific reasons ... hence unusual criteria).

Contenders – in no particular order

Windows Defender (Antispyware – this was my informal base, since it came preinstalled on system)
MSE       (Tested 2x:   once with real time protection off, second time with it on)
Clam Sentinel (with Clamwin)
Amiti Antivirus
AVG 2014
Panda Cloud Scanner
Zilla Antivirus
Comodo Antivirus
Digital Defender

Time to Boot System (seconds):

Comodo, Avira, and Digital Defender seem to have a lag relating to their real time protection turning on. 
Digital Defender booted in 68 seconds, but it took an additional 26 seconds for its real time protection to turn on.

With Comodo, the system was booted in 76 seconds, but it took an additional +70 seconds for the tray icon to appear.  Does this indicate that you don’t have real time protection for that span?  It seems to indicate that Comodo is still loading.

Avira was confusing as well.  It averaged 63 seconds to boot.  But its umbrella, indicating the status of its real time protection, was closed.  It took an additional 37.5 seconds for the umbrella to open.  This gave a total boot of 99 seconds.

CPU Percentage (%):

Note:  There is an element of subjectivity with these CPU readings.  As you can imagine, they change every time you look at them.  I recorded them when my system was idle and I checked them numerous times per antivirus to try and determine a consistent number.  Because of ranges of data, I will present them as raw data.

Defender                            30-48.5%       erratic
MSE                                    7-58%             erratic     this is with real time protection on
MSE                                    0%                                                                     protection off
Immunet                            56-67%
Avast                                  40-52%  (lingers a lot on 47.8)
Roboscan                           54%
Clam Sentinel                    40%                                               (this is with clamwin)
Amiti Antivirus                 44%
Moonsecure                       42%
AVG 2014                          38-45%
Panda                                 42.5%
Zilla Antivirus                   55%
Comodo Antivirus            27-62 (lingers on 44)   erratic
Avira                                   46-50%                            erratic
Digital Defender                53%                                 erratic
This data indicates an idle system.  These AVs utilize different scan engines that utilize your resources differently depending on what their scanning.  Just because an AV is lightest when idle does not mean it is lightest when working (ex. Opening an office suite or browser).  Subjectively speaking, when I took these AVs for a test drive, Amiti Antivirus stood out as feeling the lightest.  Clamwin likewise seemed very light but not as refined as Amiti.  Immunet was excellent as well, but had occasional small lags when opening heavy programs.  I am surprised to relay that MSE was also a light weight contender.  I felt some system drag with AVG, Avast, Panda, and Avira:  though Avira was worse.  Still, despite the slight drag, the system was usable with these.

Physical Memory (percentage):

Number of Processes Running:

This is just in case anyone is interested.  I don’t find this info very useful, but it was easy to record.  This would include my system processes.

Defender                            42
MSE                                   45
Immunet                             44
Avast                                  46
Roboscan                            41
Clam Sentinel                     44
Amiti Antivirus                  42
Moonsecure                        43
AVG 2014                           48
Panda                                  46
Zilla Antivirus                    41
Comodo Antivirus              47
Avira                                  51/47                     changes
Digital Defender                 48                          

Additional Notes:

-Digital Defender did not do a clean uninstall.  It left 83 items.  Use Revo or Wise uninstaller.
-Moonsecure gave me an application error (exception EA access violation).  I disqualified it for this annoyance.
-Clam sentinel is a two part installation.  First install clamwin, then install clam sentinel.
-given that MSE is no longer supported for XP, some of these may offer a substitute.


Admittedly, not all of these antivirus solutions are equivalent in protection.  Avast, AVG, Panda, and Avira offer capable and reliable protection.  But that protection can come with the additional system hit many can’t afford.  Weigh the protection you need with the impact your system can handle.  If you’re willing to pay, however, I’d recommend Webroot Antivirus.  It’s the hand down winner for smallest/lightest antivirus.

Boot winner:  clam sentinel, followed by Amiti
Lightest test drive:  Amiti
Physical memory % usage:  Roboscan, followed by clam sentinel

Big boys of AV run down for boot time (sorry, I don’t consider MSE a big boy anymore, they have tested poorly in all professional AV testing labs):

Panda Cloud Scanner fastest
Avast second
AVG third
Avira last

Again, it should be mentioned that my antiphishing protection skews these results.  I wanted equivalent protection and added siteadvisor to those AVs that lacked this capability.  Panda uses a proxy which would have no real system impact at boot and gives it an advantage. AVG uses linkscanner, which is potentially heavier than siteadvisor.  Avast didn’t have equivalent protection with their site rater, so I used siteadvisor with it instead.  Avira was disappointing and has no real excuses.


  1. Very cool! Thanks for doing this fairly intense research. Can't believe nobody's given you a high five for this, yet.

    Cheers for your results and work.

  2. Hi,

    Happened to see your detailed analysis on various AVs in the industry and it helps millions of users to take the right decision on selecting the right AVs according to their requirements.

    Especially, I like the depth and breadth you have done on the AVs and would give you FIVE STAR!

    Keep up the good work! Many thanks for your analysis.

  3. Great review, thanks for sharing, i will try the clam sentinel for my old laptop.

  4. Great Write, I Really Appreciate The Effort Put Itno this, Kudos

  5. thanks for all your hard work, very nice !

  6. Very Nice In need. Thanks a million. It's nice to see some real research done posted online and not that fake promoted reviewers who are getting paid by the same people who make the product they're working on. Of course they're gonna have biased opinions!

  7. Simply amazing,Sir. I must say!
    "Job done well"

  8. thank you all for the comments. i appreciate it.