Avast Antivirus Pro affecting CPU Performance

I just did a test before installing avast! Antivirus PRO and after. I am running the latest version Avast Pro Antivirus v2016.11.1.2253

I used wPRIME and set it to use all 4 cores / 8 threads of my CPU.

Before installing Avast: Score is 4.9 seconds

After installing Avast: Score is 7.2 seconds

Lower time means better so Avast! Antivirus is causing a slowdown in my CPU

This is very surprising because according to AV Comparatives, Avast is one of the lightest and got some of the best results in the performance tests: http://chart.av-comparatives.org/chart1.php?chart=chart4&year=2015&month=10&sort=1

Here are my laptop specifications:

EUROCOM Sky X9 - Intel Skylake i7-6700K 4.2 GHz | Samsung 64GB DDR4 2133 MHz RAM | GeForce GTX 980 8.0GB GDDR5 | Sound Blaster 3D Audio | 2 x Samsung 950 Pro 512GB M.2 NVMe PCIe x4 SSD + 2x Samsung Spinpoint M9T ST2000LM003 5400 RPM 32MB Cache 2TB HDD | Intel Wireless-AC 8260 w/ Bluetooth 4.0 | 17.3" LG LP173WF4-SPF1 IPS FHD Matte Screen (G-SYNC) | Logitech G602 Wireless Gaming Mouse | 2x330W AC Power Adapters | Windows 10 Pro

All AV will create some slowdown, the question is … is it something you notice in your daily use?

not really, if I hadn’t performed that benchmark, I wouldn’t have even felt it.

But what surprises me is, in the AV comparatives test listed above, it shows that Avast! is way lighter than Windows Defender, but when peforming that benchmark, I noticed the opposite because with Windows Defender the score was 4.9

Very strange, although in all honesty, I feel the system is snappier when Avast is installed VS Windows Defender

I submitted a support request maybe I can help them troubleshoot the cause of this and help others

Ticket ID: [#206115]

No, it is not strange at all.
avast has a lot more components/modules that are checking things than Windows defender has.

The more things are checked (=better protection), the more system resources are needed to do so.

Just uninstalled Avast Antivirus PRO and tried NOD32 Antivirus, wPRIME score went back to 4.9 seconds, as if there was no AV installed!

Switching back to NOD32!

You are also switching to less security.

I must say I can’t imagine how Avast can affect a pure-CPU benchmark. Disk access, network traffic… OK, could be to some extent; but CPU?
Could be some unrelated background operation (say populating of some caches) - which should disappear soon.

I wish, but the fact remains that as soon as Avast is uninstalled the wPRIME score goes back to normal 4.9 seconds

BTW, even if I disable all shields in Avast, the score is still bad, only when uninstalled does the score go back to normal

AV Comparatives Real Word protection Test / Nov2015:

AVAST 98.8%
ESET 98.7%

Live statistic taken from VT updated once a day >> https://threatcenter.crdf.fr/?Stats

at the bottom you find all time statistic, i assume this is only .exe files or Malwarebytes should be much lower

Shadow server https://www.shadowserver.org/wiki/ at the bottom left you find statistick from 0 day > 3 years

also consider that this is only scan engines so they dont have all the extra that your home AV have, like URL block …

So, it seems like switching from Avast! to NOD32 is not a such a bad idea:

Avast!..8% (5 threats detected on 59).
NOD32…62% (37 threats detected on 59).

as i said, these are only scan engines so you cant realy compare with your home AV and all the extra they have
If your home AV block the URL where on of those files reside then it has saved you

read the FAQ on those sites

Malwarebytes is Nr# 2 on the all time list

what Malwarebytes detect and dont detect

Quote David H. Lipman > Malwarebytes forum

Malwarebytes' Anti-Malware ( MBAM ) does not target scripted malware files. That means MBAM will not target; JS, JSE, PY, .HTML, HTA, VBS, VBE, WSF, .CLASS, SWF, SQL, BAT, CMD, PDF, PHP, etc. It also does not target documents such as; PDF, DOC, DOCx, XLS, XLSx, PPT, PPS, ODF, RTF, etc. It also does not target media files; MP3, WMV, JPG, GIF, etc.

MBAM specifically targets binaries that start with the first two characters being; MZ
They can be; EXE, CPL, SYS, DLL, SCR and OCX. Any of these files types can be renamed to be anything such as; TXT, JPG, CMD and BAT and they will still be targeted just as long as the binary starts with ‘MZ’.

Not listed is fileinfectors (real virus) that Malwarebytes also dont target

so if tested with all file types, statistic for Malwarebytes should be much lower as it dont target lots of files at that AV will target
also it could totally change the result for avast vs ESET, as we know avast is one of the best at detecting infected websites. There are numerous examples here in the forum that avast is the first one to detect infected websites and confirmed by Sucuri website scanner

Shadowserver
1 year statistic https://www.shadowserver.org/wiki/pmwiki.php/AV/VirusYearlyStats
3 year statistic https://www.shadowserver.org/wiki/pmwiki.php/AV/VirusThreeYearStats

Hi Pondus,

The OP wanted to switch from Avast! to NOD32 and Eddy advice him that “You are also switching to less security” which is not quite true.
There is no point to bring MBAM in this topic.

I agree with you that “If your home AV block the URL where on of those files reside then it has saved you” ; however if the AV would miss the URL , it’s engine should detect the malware on access or on execution.

I am more confident in an AV with high detection rate than in one with good URL blocking (which most of the time will introduce a lot of FP)

I used both Avast! and NOD32 in the past and I prefer NOD32 versus Avast! ; the only reason: Avast! seems to be bloated , invasive and is trying to do things way beyond its initial purpose.

Thanks!

There is no point to bring MBAM in this topic.
It was an example used to explain those statistics
I used both Avast! and NOD32 in the past and I prefer NOD32 versus Avast! ; the only reason: Avast! seems to be bloated , invasive and is trying to do things way beyond its initial purpose.
There are lots of users here that have used avast for years and never been infected, you have your reasons, others have other reasons, freedom of choise