Low Memory Usage Antivirus: Best from 25 Tested
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Keeping control over which programs launch with Windows is a proven way to keep your computer running smoothly. One of the most common culprits in hogging system resources is antivirus software.
While newer PCs may handle a few extra megabytes without issue, older systems can slow down considerably when memory?hungry programs load at startup.
To help you choose the right balance between protection and performance, we’ve put 25 popular commercial and free antivirus packages to the test.
Best antivirus with low memory usage
Antivirus software is designed to protect your system 24/7, but some are much lighter on resources than others. Here are four standout products that combine robust protection with efficient memory usage:
1. ESET
With over 100 million users worldwide, ESET is renowned for its advanced features—from comprehensive scanning (system, custom, and removable device) to built-in encryption and stolen-device recovery—all while remaining light on memory.
2. Bitdefender
Used by more than 500 million customers, Bitdefender employs artificial intelligence and cutting-edge technologies to detect and block malware across multiple platforms—all with impressively low memory consumption.
3. Total AV
Total AV not only offers real-time virus protection and daily updates but also features remote firewall access and an integrated ad blocker—all while keeping its memory footprint minimal.
4. Guard.io
This lightweight Chrome extension blocks phishing sites and alerts you to data breaches, ensuring safe and clean browsing without bogging down your system.
How We Tested
Measuring the memory usage of antivirus software isn’t an exact science. Since these programs are always active—performing background tasks and scans—the numbers can fluctuate. We focused on two key metrics:
- Working Set: The total memory used by the process (including shared memory). While this number isn’t always precise due to potential double counting, it represents the maximum non?virtual memory in use.
- Private Working Set: This metric shows the memory used solely by the process (excluding shared memory), offering a more accurate look at the program’s own resource consumption.
For each antivirus, we took 10 readings at 30?second intervals—5 minutes during idle and 5 minutes during a scan. The average scores for each product (with all associated processes summed) were then compiled. All tests were performed on an updated Windows 7 32?bit system using Sysinternals Process Explorer.
Detailed Results
Below are the complete results, listed in reverse order—from the highest (and least efficient) to the lowest memory usage. Click on any product name to visit the official website.
25. ZoneAlarm Free AntiVirus + Firewall 11.0.000.504
- Number of Processes: 4
- Processes Monitored: ISWSVC.exe, vsmon.exe, zatray.exe, ForceField.exe
- Idle Working Set (KB): 223,260
- Idle Private Working Set (KB): 191,472
- Scan Working Set (KB): 287,443
- Scan Private Working Set (KB): 226,222
24. Sophos Endpoint Security and Control 10.2
- Number of Processes: 7
- Processes Monitored: swi_service.exe, SavService.exe, SAVAdminService.exe, ALsvc.exe, ALMon.exe, SavProgress.exe, SavMain.exe
- Idle Working Set (KB): 216,482
- Idle Private Working Set (KB): 192,436
- Scan Working Set (KB): 467,817
- Scan Private Working Set (KB): 198,452
23. Emsisoft Anti?Malware 7.0.0.21
- Number of Processes: 3
- Processes Monitored: a2guard.exe, a2service.exe, a2start.exe
- Idle Working Set (KB): 131,158
- Idle Private Working Set (KB): 125,337
- Scan Working Set (KB): 251,945
- Scan Private Working Set (KB): 240,770
22. Quick Heal AntiVirus Pro 2013
- Number of Processes: 8
- Processes Monitored: ScSecSvc.exe, SCANWSCS.EXE, scanner.exe, SAPISSVC.EXE, QUHLPSVC.EXE, OPSSVC.EXE, ONLINENT.EXE, EMLPROXY.EXE
- Idle Working Set (KB): 99,090
- Idle Private Working Set (KB): 66,134
- Scan Working Set (KB): 273,984
- Scan Private Working Set (KB): 227,424
21. McAfee AntiVirus Plus 2013
- Number of Processes: 9
- Processes Monitored: McAPExe.exe, mcinfo.exe, mcods.exe, McSACore.exe, mcshield.exe, McSvHost.exe, mcsvrcnt.exe, McUICnt.exe, mfefire.exe
- Idle Working Set (KB): 142,375
- Idle Private Working Set (KB): 103,518
- Scan Working Set (KB): 239,500
- Scan Private Working Set (KB): 184,214
20. Ad?Aware Free Antivirus + 10.5.2.4379
- Number of Processes: 4
- Processes Monitored: SBAMSvc.exe, adawarebp.exe, AdAware.exe, AdAwareService.exe
- Idle Working Set (KB): 162,540
- Idle Private Working Set (KB): 118,728
- Scan Working Set (KB): 189,223
- Scan Private Working Set (KB): 144,394
19. Bitdefender Antivirus Free Edition 1.0.14.889
- Number of Processes: 2
- Processes Monitored: gziface.exe, gzserv.exe
- Idle Working Set (KB): 115,559
- Idle Private Working Set (KB): 91,742
- Scan Working Set (KB): 135,836
- Scan Private Working Set (KB): 115,795
18. Trend Micro Titanium Antivirus + 6.0.1215
- Number of Processes: 6
- Processes Monitored: uiWatchDog.exe, uiSeAgnt.exe, coreServiceShell.exe, coreFrameworkHost.exe, AMSP_LogServer.exe, WSCStatusController.exe
- Idle Working Set (KB): 102,208
- Idle Private Working Set (KB): 72,754
- Scan Working Set (KB): 161,926
- Scan Private Working Set (KB): 130,022
17. Avira Free Antivirus 13.0.0.3499
- Number of Processes: 6
- Processes Monitored: avgnt.exe, avguard.exe, avshadow.exe, avwebgrd.exe, sched.exe, avscan.exe
- Idle Working Set (KB): 63,754
- Idle Private Working Set (KB): 41,138
- Scan Working Set (KB): 199,264
- Scan Private Working Set (KB): 157,750
16. VIPRE Antivirus 2013 6.2.1.10
- Number of Processes: 3
- Processes Monitored: SBAMSvc.exe, SBAMTray.exe, SBPIMSvc.exe
- Idle Working Set (KB): 114,098
- Idle Private Working Set (KB): 91,981
- Scan Working Set (KB): 134,488
- Scan Private Working Set (KB): 104,936
15. NANO Antivirus Free 0.24.0.52214
- Number of Processes: 2
- Processes Monitored: nanosvc.exe, nanoav.exe
- Idle Working Set (KB): 176,141
- Idle Private Working Set (KB): 53,846
- Scan Working Set (KB): 287,284
- Scan Private Working Set (KB): 131,201
14. ESET NOD32 Antivirus 6.0.316.0
- Number of Processes: 2
- Processes Monitored: egui.exe, ekrn.exe
- Idle Working Set (KB): 93,616
- Idle Private Working Set (KB): 76,441
- Scan Working Set (KB): 103,244
- Scan Private Working Set (KB): 82,913
13. Dr.Web Anti?virus 8.0.8.04230
The details for Dr.Web are as follows:
- Number of Processes: 6
- Processes Monitored: dwarkdaemon.exe, dwengine.exe, dwnetfilter.exe, dwscanner.exe, dwservice.exe, spideragent.exe
- Idle Working Set (KB): 92,006
- Idle Private Working Set (KB): 66,822
- Scan Working Set (KB): 117,973
- Scan Private Working Set (KB): 90,430
12. Kaspersky Anti?Virus 13.0.1.4190
- Number of Processes: 2
- Processes Monitored: avp.exe, avp.exe
- Idle Working Set (KB): 65,625
- Idle Private Working Set (KB): 52,218
- Scan Working Set (KB): 103,377
- Scan Private Working Set (KB): 92,105
11. Bitdefender Antivirus Plus 2013 16.28.0.1789
- Number of Processes: 5
- Processes Monitored: bdagent.exe, downloader.exe, updatesrv.exe, vsserv.exe, odscanui.exe
- Idle Working Set (KB): 81,360
- Idle Private Working Set (KB): 47,658
- Scan Working Set (KB): 150,478
- Scan Private Working Set (KB): 62,877
10. Microsoft Security Essentials 4.2.223.0
- Number of Processes: 3
- Processes Monitored: MsMpEng.exe, msseces.exe, NisSrv.exe
- Idle Working Set (KB): 70,484
- Idle Private Working Set (KB): 51,750
- Scan Working Set (KB): 79,103
- Scan Private Working Set (KB): 57,787
9. F?Secure Anti?Virus 12.77 build 100
- Number of Processes: 7
- Processes Monitored: fsgk32.exe, fshoster32.exe, FSM32.exe, FSMA32.exe, fsorsp.exe, fssm32.exe, fsblsrv.exe
- Idle Working Set (KB): 62,042
- Idle Private Working Set (KB): 40,246
- Scan Working Set (KB): 92,386
- Scan Private Working Set (KB): 66,819
8. AVG AntiVirus Free 2013.0.3272
- Number of Processes: 7
- Processes Monitored: avgcsrvx.exe, avgemcx.exe, avgidsagent.exe, avgnsx.exe, avgrsx.exe, avgui.exe, avgwdsvc.exe
- Idle Working Set (KB): 194,888
- Idle Private Working Set (KB): 34,398
- Scan Working Set (KB): 199,628
- Scan Private Working Set (KB): 63,403
7. UnThreat AntiVirus Free 2013 6.2.37.17222
- Number of Processes: 2
- Processes Monitored: utsvc.exe, UnThreat.exe
- Idle Working Set (KB): 13,615
- Idle Private Working Set (KB): 8,953
- Scan Working Set (KB): 87,027
- Scan Private Working Set (KB): 73,778
6. Immunet 3.0.8.9025 Free
- Number of Processes: 2
- Processes Monitored: agent.exe, iptray.exe
- Idle Working Set (KB): 40,413
- Idle Private Working Set (KB): 29,304
- Scan Working Set (KB): 63,475
- Scan Private Working Set (KB): 45,510
5. Norton AntiVirus 20.3.1.22
- Number of Processes: 4
- Processes Monitored: ccsvchst.exe (x4)
- Idle Working Set (KB): 59,304
- Idle Private Working Set (KB): 19,362
- Scan Working Set (KB): 111,094
- Scan Private Working Set (KB): 52,576
4. Panda Cloud Antivirus Free 2.1.1
- Number of Processes: 4
- Processes Monitored: PSUNMain.exe, PSUAService.exe, PSUAMain.exe, PSANHost.exe
- Idle Working Set (KB): 31,714
- Idle Private Working Set (KB): 20,340
- Scan Working Set (KB): 76,498
- Scan Private Working Set (KB): 41,172
3. Comodo Antivirus Free 6.1.275152.2801
- Number of Processes: 4
- Processes Monitored: cavwp.exe, cis.exe, CisTray.exe, cmdagent.exe
- Idle Working Set (KB): 39,664
- Idle Private Working Set (KB): 14,954
- Scan Working Set (KB): 105,317
- Scan Private Working Set (KB): 34,453
2. Webroot SecureAnywhere AntiVirus 2013 8.0.2.127
- Number of Processes: 2
- Processes Monitored: WRSA.exe (x2)
- Idle Working Set (KB): 3,823
- Idle Private Working Set (KB): 2,726
- Scan Working Set (KB): 9,949
- Scan Private Working Set (KB): 7,673
1. Avast! Free Antivirus 8.0.1483
- Number of Processes: 2
- Processes Monitored: AvastSvc.exe, AvastUI.exe
- Idle Working Set (KB): 9,706
- Idle Private Working Set (KB): 4,290
- Scan Working Set (KB): Resets every 10 seconds
- Scan Private Working Set (KB): Resets every 10 seconds
Results and Summary
The result tables were split into two parts—one for idle memory usage and one for usage during a virus scan. Colors in the tables indicated performance, with green marking the lightest antivirus, yellow the second best, orange for the next most memory?hungry, and red representing the heaviest resource usage.
Average Memory Scores:
- Idle:
- During Scan:
Key Observations:
- A few antivirus packages used nearly 200MB on average while idle. ZoneAlarm, for example, registered very high numbers—though note that its inclusion of a firewall can affect these figures.
- On the efficiency front, Webroot SecureAnywhere shines as a cloud?based solution with extremely low memory usage and minimal shared resource overhead.
- Avast, one of the most popular free antivirus options today, managed to keep its memory usage impressively low by flushing its memory every 10 seconds during scans.
- Some surprises emerged: Comodo has improved its efficiency over time, while Avira—once known for being very light—now shows higher memory consumption, especially during scans. Bitdefender Free also showed some fluctuation, yet overall its memory usage remained on the higher side.
Final Note:
While these results focus on memory usage, remember that they don’t cover all factors such as feature set or detection rates. A slightly heavier antivirus might offer extra features or superior protection. Use these findings as a guide if you’re looking to switch to a more memory?efficient antivirus solution.
Sir, thank you for the work you put into this.
This was a fairly comprehensive comparative review of many AV. It addressed more or less the information I was searching for (would be nice if CPU usage was included) but memory usage gives a fair idea.
I really appreciate the time and work you put into this. Keep up the good work on this blog
Thanks so much this test help me a lot
but x-ray2.0 and smadav is still the best
I have NOD32 and Malwarebytes on my pc and working very well together.
Malwarebytes is very very ligth!
nope
liar
it ram usage high
A program being “light” on resources is more than just RAM usage, there’s other things like CPU usage and HDD usage to also take into consideration.
MBAM’s memory usage is what I would consider high but it’s not bad for disk usage and CPU usage. It may be a stretch to call it “very very light” overall but one person might think it’s light on resources where someone else would consider it heavy on resources. There is no right or wrong, truth or lies in this situation, just opinion, and that user gave their opinion.
Searching for an AV program the uses few resources sent me to this comments page.
I agree that MBAM (Professional 4.3.0) uses a lot of memory: around 377MB currently on my machine, and it’s scan can take up to a half hour on my laptop (HP Pavilion TouchSmart 2.4GHz, 16Gig SDRAM, 1TB HDD) during which time other programs can run very slowly. I ditched BitDefender about a month ago for the same reason.
And as a point of reference: ChkDsk and SFC find no errors and the HDD is 100% defragmented.
I just read this review for the first time and it impressed me quite a bit.
As a geek, I try to stay current, but unless you specify your search to include system usage when looking for the top antivirus, you just get the standard results.
This standard result is effectiveness of protection but leaves out system hog reports.
What may well provide the most secure may also lend to system drag.
I wish that this type of testing was done on any page that is reporting top 10.
Thank you for your had work.
Can one have his or her cake and truly eat it too?
thank you, where is the processor usage report?
I wished you would have tested 360 Total Security too because it is tested very positive.
Excellent review, thank you so much !!!
I’ve been trying to find a small footprint AV for Windows XP and Avast and BitDefender both have the typical >200mb service running in the backround. Oh, and I was using AVG free when I decided enough is enough. And this is not on just one PC, but many running XP at office and at home. I wonder if AV s/w installs full protection because XP is unsupported? All I want is a AV that runs a nightly scan – and that was what BitDefender was claimed to do.
You realise that XP with an antivirus doesn’t protect you as the OS does not get security fixes anymore without the embedded XP hack. Just hope you don’t do any online banking
Of course having a product that does not slow you down is better. Coding is of course a key factor to that extent.
Meanwhile some product adpat their memory consumption to the use so that it takes more CPU / Memory to run analysis when idle (when you’re afk) and do not bother you when athe PC is actively used.
Second but also important, ranking AV on the memory is just leaving aside that the best protection is not just the lighter but most of all the one that protects you best!
What the use of a solution that weight nothing but let pass thoushands of threats?
Same thing the otherway round, a very heavy solution that blocks even genuine programs will waste your time and patience.
It’s all a question of compromise, and yes, having a bulletproof solution has a cost, both is money (yes these developers are not working for free, are you?), and memory :)
That is why we made it clear at the end of the article that this is one test, to test memory usage, and nothing else. It is not for the best overall, the best detection rates or the fastest, just plain and simple RAM consumption during use.
Hal, that was a very good test. And yes, you did explain it was only based on memory and nothing else. Very plain comment for all to see :)
It would be nice to see the summary sorted to memory usage as it is the purpose of this article. Presenting it in alphabetical order is not effective. Good test though.
It’s easy enough to read with the best and worst highlighted. When or if this gets an update we’ll probably use bar charts instead.
I think that MalwareFox is also worth a mention here, it was consuming about 30-50 megabytes at idle and 100 something when scanning.
Hahaha. I have Avast and was just wondering once again iff I should renew and get something else.. :) I see I do not. I can’t believe it, how well it has worked and yet how silent it stays. I love my Avast and hope it remains as it is. I was also thinking this. If a anti-virus wants to be true to it’s name it should be that way; stay undetectable to any virus until it attacks or other. then once it does the Anti-virus kicks in and shuts that Sheeeet down there and then.
Dang, I wish I would have renewed Avast. I decided to give McAfee another try since I was able to get 1 year for $25, I should have stuck with Avast because McAfee sucks. :( Aw well I’ll just get Avast again this June :)
Thanks for all the reviews and testings you did., I always check this site before downloading the needed software.
As I did also when needed a free virusscanner, when noticed the MSdefender was eating lots of recourses, it is become fat in Windows10 64bit. So I did download Avira free and while using this software I also noticed that the memory usage is now being reduced, only this software does cause an hudge memory leakage., as I did check the activities from Ntoskrnl.exe in the taskmanager. Now I did the same on my sons system only now I did install Panda free, here the same results.
The total memeory uses is even more then MSdefender. No drivers or software was intalled afterwards so this is pure caused by the antivirus software of Avira and Panda free. So leaving MS defender does not help when you want to reduce the memeory.
I have 8ram installed btw.
is it malwarebytes one of antivirus app ? and why not listed above ? any suggest for me ^_^
Malwarebytes is not classed as a full antivirus and is more something you use along with your antivirus software.
now it is
yes, it is now an almost fully fledged av and it would have topped the list for using highest amount of memory ~300mb when in not running any scan.
First, I’d like to congratulate how extensive this article was, testing 25 programs is no joke, although it can be funny (pun intended).
Now, to contribute a little of my self: Please make an updated post, while also taking into account the Disk I/O [Reads and Writes to the harddisk/SSD].
Some programs, like Avast and AVG, even idling, do not even let the harddrive usage leds go off anymore.
For the last 12 years or so, I saw a huge increase on resources taken by Antivirus, especially Disk I/O.
The impact of that is a system that becomes sluggish while scanning, and sometimes during idling [background scans].
Another Reason is not to waste your precious SSD lifecycle [reads and writes], because that aspect is not well tought of in modern antivirus programs, correct me if I’m wrong.
A lot can change in three years since this article was posted, I wonder If Webroot is still one of the best memory performers
Here’s a little update for you. I am currently testing (4 days into my 14 day free trial) the latest release of Webroot and have to say it’s quite astounding in terms of efficiency. Never seen anything like it before and I’ve tried most. The last offering before Webroot was the latest AVG Free. Had to give that one a misss as it used over 350MB of ram on idle and slowed browsing to a snails pace. It did catch the bad guys and was a nice package overall but the strain on my single core cpu consigned it to the rubbish bin. XP is fully compatable with Webroot and it installed a breeze only uses 3-5 MB of ram too whilst browsing and virtually NO cpu resources.
OK so I know you’re thinking I work for these guys but here’s the truely amazing bit. I don’t.
It is. My subscription just expired, but SecureAnywhere Internet Security (2016 version) was using less than 5 MB at idle.
It’s funny, being a geek I did a test like this myself over the past 12 months on the 2015/2016 versions, using pretty much the same process as these guys did. Biggest surprise was Bitdefender (paid versions) using so much memory (200MB plus at idle – almost as much as McAfee!). Yet the labs and most reviews praise it as being light. Another surprise was ESET (130MB) which in years past, geeks loved. But, I’m not using any product that uses that much memory. Typically it means it’s coded poorly.
So I have spent quite a bit of time trying to find a *basic* real-time always-on Anti virus that uses less memory than Windows Defender and provides better protection. Windows Defender on Win 10 uses about 60-65MB at idle. I don’t want a “suite” with tools like shredders, privacy checkups, etc that are useless to me personally. With that said, I’ve been using either Panda Free Antivirus 2016 (uses 30MB or so); Avira Pro (uses 60MB or so); Trend Micro Antivirus + (uses 65MB or so); and the “new” Mcafee Free Cloud AV, which is in beta but works great (uses 30MB or so). Norton Security (30MB) is also lightweight but has more features than I need.
I will most likely settle on the Panda Free or McAfee Free Cloud AV for now, as both provide the simple, lightweight protection I want. I also use Malwarebytes Free / HerdProtect as an occasional on-demand scan. And Mcafee Site Advisor (now called “WebAdvisor) is a lightweight (5MB) web broswer protection tool that uses very little memory and can be used in addition to your always-on AV protection – it rates websites and blocks phishing sites. I understand this particular set up is not for everyone, but if you’re an “advanced common sense” user, this is really all you should need…
High memory usage from an av can mean it’s not well coded but is not the case everywhere. For example some will store all or part of their signature database in memory to improve speed at the expense of used memory, that isn’t bad coding but just improving performance in another area.
That is the reason antivirus such as Panda is lower on memory because most of its work is done in the cloud. This can cause performance issues when scanning or detecting viruses as it keeps having to contact a server while a locally stored database can process much quicker. So where you gain in one area you might lose in another.
As pointed out in the article, higher memory usage does not automatically translate to a worse product, and as the old saying goes, unused memory is wasted memory…
I’ve been running Avira for years but just unistalled the free version, The resource hog was just too much to deal with. Now I’m searching for a replacement that won’t hog all the resources. Thanks for the article.
Like 8 months ago I made some test myself and came to a similar conclusion. Avast Free has fewer binaries running in the background and are small ones.
It may not be the fastest, or the most feature rich, or the most secure (but has very good independent ratings btw). But you can’t argue the resource usage without the GUI is pretty damn low…
Exactly what a gamer needs.
Sadly they don’t offer 64-bit binaries. So it has some background weight on compatibility layer, but also most AV solutions either free or commercial share.
I really dont agree with avast being chart topper as what my experience is if you have a i core processor with 2gb+ ram then it is the best but with a old configuration i.e. 1gb ram and pentium processor you have to go for webroot or even bitdefender is an excellent choice and my personal favorite is definitely BitDefender and ESET NOD 32. Believe me I have tried almost all but none matches Bitdefeneder or ESET on antivirus protecttion+memory usage.
Of course you don’t have to agree but we produced some hard numbers with this test and it wasn’t our opinion, but fact based results. Avast was and still is one of the lightest antivirus around and one of very few that can still go on a low memory PC/laptop. ESET Smart Security for example, is currently using nearly 200MB of RAM on my computer.
Going to be running an id quad core 3.3ghz with 8 gb of ram and will be doing a lot of gaming on this new computer. I am thinking of going with Bitdefender but am concerned about how much of a resource hog it is. What are everyone’s thoughts?
bitdefender is veeeery resource hungry! if youre into pirating or other shady bussinesses (no shame to admit at this point) u should go with kaspersky. for once u can reset the 30 day trial each time n also has a well acknowledged protection n on top of that is also (considering its reputation/protection level) eficient!
i dont have no particular numbers to hand, but i remember it wasnt burdening my pc…
right now ive switched to avast, since ive nough experience to know what im doin :D
I agree that this test needs updating. Im running Bitdefender Total Security 2015 and on idle it uses less than 8mb RAM. Scanning a 4GB exe put usage just over 30 and was done in under 5 seconds. And not to mention its been killing the competition in the West Coast Labs and AV Comparatives tests past 4 years or so. Get what you pay for and you should expect free many times to mean inferior in comparison to the companies top shelf products.
I have to join the the consensus on avast, even after a new computer, it did seem to noticeably slow things down. Especially with web protection enabled.
Avira or 360 Security Essentials are a much smaller hit on resources and performance.
Really, Avast? This is bad news, I’ve entered here to find something lighter than Avast. It’s always causing terrible bugs and heavy start ups here
I’ve tried Avast,it caused Chrome to take forever to open, Panda kept cutting off my wireless utility, Bitdefender worked good but used a lot of memory, AVG, was nice but used too many resources. This test needs a severe updating.
I’ve been using Avast for several years on old machines, it’s still one of the lightest and one of those that gives me the least amount of problems.
Joe 2 months ago
I was using Bitdefender which is supposed to be light on resources. It more than doubled my boot time to something like 3 minutes and 36 seconds and constant hard drive thrashing on a 2.8 Ghz Pentium 4 with 2GB of ram. Even when I closed the program there was still a process running slowing down the computer. I deleted it and I feel like I’m on a 3.8 Ghz quad Core I7.
Joe This is because you have boot scanning on at start up, to fix go Protection, antivirus, under the Shield tab go custom, Miscellaneous tab and untick “Early boot scan”.
Cheers
I was running AVG its so crap memory eater and and for a long time i had problems with my music production as it was taking 324,547 kb i couldnt work it out till i came here.i uninstalled it did a windows reload and so and behold no more problems ive just my firewall on and defender everything seems to be A1 now.it was causing all sorts of latency and because i have 6TB OF HDDS for my database,s i needed to sort something great site very helpful.
I was using Bitdefender which is supposed to be light on resources. It more than doubled my boot time to something like 3 minutes and 36 seconds and constant hard drive thrashing on a 2.8 Ghz Pentium 4 with 2GB of ram. Even when I closed the program there was still a process running slowing down the computer. I deleted it and I feel like I’m on a 3.8 Ghz quad Core I7.
Sadly all the free AVs are nothing but resource hog anymore. I had to remove Panda Cloud anti-virus because it was causing the blue screen of death. Clamwin is the one that is not a resource hog at all.
Friends computer Dell Inspiron N5010 was running slow. 93% memory was being used. Removed AVG 2015 and the memory usage dropped to 50%. The computer had 2GB Ram with windows 7
not true anymore for Avast 2015 10.2.218
AvastSvc.exe: 57.340K private bytes, 41.160K Working set
my overall ram and cpu use was also less when using Avira (which I replaced with Avast because of the promised lower memory).
Latest avast is not light, i think its v 10. frikin heavy about 600MB on hard drive which is a lot and as for memory goes well not good (for low end PC’s). comes with lot of shiit(=tools and other stuff) now which is not usefull for common user.
I have been using avast AV free for a long time but I find during an auto update of virus data files, the program uses a lot of system resources.
Thank you.
Would really appreciate an updated set of figures here for 2015 releases! You did a wonderful job of isolating this information, but from the chatter going on things have changed a bit over the last year…
Needs updating…. Avast has become a bloatware as of version 10
Not quite sure what you mean by bloatware, in terms of memory usage it uses about 7-8MB more than the version we tested. That would still put it in the top 2 here…
I am running bit defender. Latest 1.021.2099 as of 2014.07.10 It’s running around 20mb for two processes. I guess it improve a lot since this test. I also know that this is top AV in terms of catching the bug. Not as low as avira, but I will take extra safety any day.
BTW: Beware – 1st 5 min of booting it will take upto 200mb of RAM, but then it behaves well.
Try Webroots new Secure Anywhere suite.Its so light you have to experience it yourself.That is not enough,it has to block all malware too,and it does.Look it up,its great.
avasts flushing is confusing. it will access disk each time and slow system. plus, what is average memory per given time frame. irregardless if it flushes or not, it has an average memory. I suspect it is far less than webroots.
Also include this antivirus test – “Baidu Antivirus”. I found this one is very good with cloud scan, light weight and also free. Love to hear from you Raymond.
thanks
I used to recommend AVG earlier but since Avg used to take a long time to delete viruses after scanning so i thought of changing my antivirus and gave Avast a try since then i got no problem good features and UI and fast too i recommend every friend of mine for Avast.
I was using AVG but have trouble upgrading then switched to Avast. My Lenovo laptop has a feature that tells me how many seconds it takes to boot. With AVG installed the time always creeps up to about 50 sec. With Avast, the time is around 30 sec plus. Have to add that this boot time is not entirely accurate as it takes longer than that until I can actually use the computer.
Test 360 Internet Security and Baidu AV.
useful when I decide a new one when my bitdefender license gets over… thanks
Thanks for the article but I’d also like to re-iterate what others have already said: that disk IO is much more relevant to an Anti-virus package’s lightness.
We used Kaspersky in our office a few years back and even with the background protection service turned down to its least aggressive settings, it would often bring the hard drive to its knees slowing down all applications in general.
I have MSE (RealTime File Monitoring), Comodo v5.10 (Firewall+Defence), Vipre AV Premium (WebFilter), Baidu AV (USB Scan+Ejector), MalwareBytes AM(Manual Scanning Only), McShield (USB RealTime Scan) – all RUNNING side-by-side. I never had any issue with them.
I’ve tried Avast, Nano and Kaspersky on Core2DUO+4GB RAM (Win7 x64 Ultimate), everyone of them made my computer run super slow.
why u use so many AV? one is enough to protect u from virus attack. Most of the time using too many AV will not detect any virus. It just slowing down your system dude.
Actually what you are telling just prove your ignorance about these software, as Shes not using all these software to do the same things… many antivirus like Avast , MSE for exemple, then this would be a problem, but all his software do a different thing, thats what we call : “antivirus combination power” which mean that only one software to protect you for free cannot be enought without a combinatioon with another program to complete the other, like Avast paired with Malwarbyte for a great virus detection while having perfect malware one…
I tried Avast on an old Shuttle PC with 1 GB RAM and Athlon XP2200+ (1.8 GHz) processor. Memory load remained low, but processor usage was around 50%, even with the system running idle. Too high for my taste and I removed Avast. Looking for a really light solution…
I used various A/V in my system and after some months of installation those made my system run very slow. The only one which works perfect for me is nod32 smart security. May be at initial stages these will work good but try to check the same after some months of installation.
Please review Kingsoft Cloud Antivirus. I have been having fantastic results with it. I am quite surprised that it doesn’t get any attention.
Baidu bought Kingsoft. So imo it’s better to test Baidu. They’re using their own cloud + Avira engine.
How does this even matter when computers have 4Gb plus RAM and barely use 1-2 at a time ? It would matter when resources are scarce and I doubt if that is the case for most users, at least in developed countries.
You’re making a rather huge assumption that “computers have 4Gb plus RAM” when nothing could be further from the truth. Only in the last 3 or 4 years have most off the shelf computers come with that amount of memory. Before that, it was mostly 2GB or 1GB.
Look at a few recent hardware surveys; Steam says around 1/3 of their gamers have <4GB of RAM, Unity Web Player says around 60% of their users have 2GB or less. Granted, they don't represent the majority of the worlds users but they do show a trend, LOTS of people don't have anywhere near 4GB of RAM, "developed country" or not. And for them, this article might be useful.
What percentage of home PC’s have 4GB of RAM, 20%? I bet at least half have 1GB or less, and half of those 512MB or less. Memory creep with versions is a HUGE problem with those of us keeping the far away parent’s e-mail/facebook PC’s running. AVG was a classic example, it brought so many PC’s to their knees with increased memory usage version to version.
Thanks for the tests, but I don’t know what you mean when talking about Bitdefender. “it still consumes a lot of memory for a program with virtually no features or options.” is the part I am talking about. Virtually no features or options? Am I experiencing something different because I’m using the pro version?
I just switched to Bitdefender after using Avira for several years and Avast for a short while (they scared me off when they started plastering me with e-mails to renew my license 2 months before it was due, Avira scared me off with their fairly hidden option for auto-renewal of the license that was never presented to me during purchase – they did refund me, though).
Best AV software I have used to date. Have tried many others, but the balance between effectiveness (only what I can gather from AV tests) and performance is superb. Add to that the easy to work with sandbox and for me it’s feature complete.
Will stick with this for at least another year (license) and then probably reevaluate, but just wanted to point out my confusion with your statement.
The free BitDefender is completely different to the paid versions and was widely criticized when released because it had virtually no options to configure it at all. There have been a few things added since the initial release, but the differences between free and paid Bitdefender is still vast.
WOW !!! Thank You So Much ! Very nice & professional article & site. God bless you.
This is exactly what I was looking for. Much more convenient that testing each of them for myself. I would like to see CPU usage in the next one. Thanks so much, Raymond! :)
I’m using Dr.Web Security Space,it is by my opinion,one of the best protections ever and it have a very small resourse usage,on newer pc-s,you won’t even notice that you have an antivirus….
Thanks, just what I was looking for. Been a user of avast for years and was surprised that it was the lightest one all along.
Brilliant. Exactly what I was looking for. Thanks!
Hello, i see that avast! is the lightest,
but what about avast! Internet Security and avast! premier ?
have the paid version of avast the same memory usage because im planning to buy avast! Premier !
or can anyone guide me of i should buy it or not, or should i go for the free version ?
Thank you.
Webroot has always been my #1. Unfortunately, it’s way too expensive for individuals. Their so-called discount every once in a while is a) US-only and b) not a real discount. How come I get a legal one year Norton AV license for 5 bucks from a *certified retailer* and for Webroot I have to pay 4x as much IF it’s on discount LOL. Wish they’d offer a free version or at least a one-computer/one year license for 10 bucks.
Webroot is indeed cute. Bought a license some time ago on ebay for 10 bucks. Good price.
Thank you for a very great post.
Very good test, I agree with you! I use Norton on all my PCs!
I am currently looking for an av that is light yet effective for my netbook. I been using panda antivirus but it skips some files that is infected then i used avg it more effective but it clogs my system. I read comments in this article, no one notice the performance of ESET, I believe it has the best and yet light av base on your experiment.
I’m using windows XP with the current Avast! updates and Avast! only consumes less than 6mb when idle and while watching CPU usage I never see 1% appear. When opening Avast! and starting a system scan. It consumes an average of 32mb and CPU usage average 9%.. The only time I notice a stange memory usage is when stopping a scan for the memory jumps up and down between 50-130mb until it idles back under 6mb.
Could you please test also Baidu Antivirus 2013?
And how do you select only some processes in Process Explorer (or you modify screen image?)
It would be very nice if you colud select some rows in Process Explorer like in Excel and show you somewhere the sum of parameters, or sort on selected and show sum bellow (maybe you could propose to Mark – author of Process Explorer).
using avast with custom component installed.
avast has 2 processes and consume 40 mb RAM when idle.
though avast is best AV so far.
An AV using more memory doesn’t mean that it’ll cause poor performance than an AV using less memory. Some AV LOAD THEIR VIRUS SIGNATURE into the memory to achieve better performance, while OTHER AV ACCESS THEIR VIRUS SIGNATURE FROM HARD DRIVE. There are more I/O reads/writes with AV accessing virus signature from hard drive and poor performance compare to AV with signatures in memory. As we all know memory is faster than hard drive.
An AV using more memory doesn’t mean that it’ll cause poor performance than an AV using less memory.
Exactly! That’s the part what many people don’t understand.
Consuming more memory will surely cause poor performance if the ensuing lack of free memory causes swapping. I have Norton AV and it normally consumes around 100-200MB. Sometimes Firefox will use up to 1GB or memory and as a result, Norton climbs up to 1GB or higher. Now my machine is swapping like crazy, performance sucks, etc. Killing Firefox causes Norton memory to go back down after a while. But this is the case where the Av using memory will cause poor performance.
System is a Dell D810 with 1.8Ghz processor and 2GB memory.
Thanks for publishing the results but it would have been nice if you sorted the results based on values vs. alpha of product names….real PITA to figure our 2nd 3rd etc placements. We use Vipre Ent. and its usage is barely noticed by users even on 5+yrs old HP desktops running XP. However, just because AV is light on resources doesn’t mean it is ‘good’.
Thanks.
I dont go by any data published in websites. I personally tried many free antivirus and I settled with Avira free. For my system it is the lightest. Avast is definitely a resource hog. With Avira my system boots up in less than 30 seconds.
Memory usage is not relevant enough. A lot computers now have 4GB or more so 200MB occupied by an AV is not that much. Most important is CPU use and HDD along with real impact on day to day use.
Apparently you are not working with wide variety of computers, outside the business world. Many ordinary people are using older computers that have good enough CPU processing power, but are bogged down by lack of RAM.
Not everyone buys a new computer every few years and that is actually wise. Sadly, some “wise” nerds force these people to buy a new computer, when actually they only need a RAM upgrade.
Even then, useless RAM hogging is not acceptable. But neither is high CPU and/or I/O usage.
I agree with you, but again, memory is not the only factor to know if an AV is slowing down the system or not. Jason is having a good point explaining about the I/O read/writes on HDD. HDD stays the slowest component of a PC. It would have been nice to go a little deeper in the tests.
Anyway if you look at your tests results it’s actually quite right. WebSecure is the lightest, I tried it for months and it has definitely a low impact of performance, however interface is weird. The new Avast is also surprisingly lite, I need do to more tests but I’m quite satisfied with it. Windows Defender is not present but it also quite fast, however it slows down some operations like copy/paste somehow.
I don’t know Panda, Imunest, Unthreat and Fsecure.
Then the biggest ones, Norton, BitDef, Kasp & company are just gas factory and even if BitDef has a no brainer mode, it still has an important impact on perf. You can see it using some skydrive upload with word or just running quite a few programs and surfing on the web.
using Avast for some time now (1 year or more) as Avira became obtrusive I changed options in Avast to not allow animation of the icon in the tray area nor do I allow or care for any pop ups though some do show but very minimally.
The only time that Avast slows down my computer is when first booting up as it checks for updates which is fine.
I am using XP Pro sp3 x86, 1GB of ram memory on my antiquated socket 939 SLI with 2x Alpha Dog edition 8800GS 384MB video cards with no issues other then the initial boot up of the operating system.
Thank you for this article,very much appreciated.
I will have to agree that process I/O (reads writes) will give you much better results than testing memory.
Most newer system have at least 2GB of RAM which more then enough to run most AV’s without any system slow downs. However when it comes to programs like ZoneAlarm Free Antivirus + Firewall, it doesn’t seem to effect the system response time like Avast Free does even though it uses more memory. on my system. I never have never experienced system lags using ZoneAlarm but I have occasional lags with Avast Free.
Comodo for example is very light on memory usage but kills system response time probably because it has to check all of the process I/O (reads writes) where others only check suspicious process I/O (reads writes). I had to uninstall Comodo because the system lags got to be too much of a problem to handle. This applies to all products that use advanced HIPS, even though they may use little memory they still make your system response time much slower. Testing just memory usage will not give accurate results.
If process I/O (reads writes) was tested you would see much different results. Hopefully Raymond will tackle testing process I/O (reads writes).
Raymond, what’s your view on Agnitum’s Outpost Security?
I’ve been using it since a long time,and it seems quite light on the system…
Avast is a resource hogger – I removed faster than I’ve installed!
I see Avast get great ratings all over the Internet, but if it’s so great, tell me this. Why in the world does it “bog down” the operations of certain machines? This can be at random, new or old PCs, but, whenever you click on a program to start it, you can see the Avast “ball” spin…and spin…and spin before the program actually starts. This can also happen when simply opening a document. I understand the program is “checking for viruses”, but seriously, why does Avast take so durned long to “check”?
At this point, can’t recommend it as a free option to my customers because of this.
Thank you for the article Raymond. I like the Final note which you written. Next time also include Avast internet Security in the test.
Thanks for the article – as other people have mentioned it’d be great to see a comparasion of usage in terms of IO Reads/Writes… disk access time and second processor active time.. Memory these days is cheap (I only have 8GB and even that’s hardly used in comparasion to HDD access time…. but by adding another 16GB i wouldn’t see much of a difference since antivirus keeps wanting to read hard disk directly) … i’d say a lighter antivirus could have a much larger memory cache?
These should also be compared on how effective each finds a virus, which when it does, might also increase memory used; and how long an active scan takes. A program that doesn’t use much memory could be because its designed to find little.
If you have time you should test process i/o (reads writes). It is more important than memory test if you want to know how av affects your system.
I’ve been using Avast! for a couple of years now and it has by far been the best I’ve ever used. I gave up on Norton and McAfee because they were memory hogs, hard to use and not getting along with software. Avast! really made a difference on my memory and CPU and has protected me from all kinds of nasties on the internet. Plus it’s easy to use….
Thanks for the article, Raymond. Interesting and informative as always, Putting this one in my library for future reference.
Would love to see this same article done for android phones. That’s an area where memory usage really needs to be tracked. I’ve tested 1/2 dozen myself and none have been a good fit, in fact some that have memory managers built in seem to slow my phone down…
Not sure Avast flushing it’s memory every ten seconds is that good a thing. For a start I suspect it’s just being flushed to virtual memory. As to Avast being the most popular I have seen loads of people leaving them since Avast 8 was released due to bugs and other issues. I personally left them because they hype themselves more than Apple ever has.
With Avast you can have a cup of tea in between double clicking an office document and it is made ready to work with. Avast may not be a memory hog but most surely a system bog. It has compatibility issues with several other programs also. So, as Raymond rightly pointed out, readers don’t translate these results to the performance of the AVs. What we want is good balance between needs and deeds of the AV.