Thursday, April 13th 2023
Microsoft Fixes Windows Defender Bug After Five Years of Firefox Slowdowns
Microsoft's Window Defender engineering team has finally found the time to address a long term bug within its anti-malware software - relating to performance issues with Mozilla's Firefox web browser. User feedback stretching back to five years ago indicates extremely sluggish web surfing experiences, caused by a Windows "Anti-malware Service Executable" occupying significant chunks of CPU utilization (more than 30%). The combination of Firefox and Windows Defender running in parallel would guarantee a butting of (software) heads - up until last week's bug fix. A Microsoft issued update has reduced the "MsMpEng.exe" Defender component's CPU usage by a maximum of 75%.
Microsoft and Mozilla developers have collaborated on addressing the disharmonious relationship between Defender and Firefox. A plucky member of the latter's softwareengineering team has been very transparent about the sluggish browser experience. Yannis Juglaret has provided a string of project updates via Mozilla's Bugzilla tracking system - one of his latest entries provide details about the fix: "You may read online that Defender was making too many calls to VirtualProtect, and that global CPU usage will now go down by 75% when browsing with Firefox. This is absolutely wrong! The impact of this fix is that on all computers that rely on Microsoft Defender's Real-time Protection feature (which is enabled by default in Windows), MsMpEng.exe will consume much less CPU than before when monitoring the dynamic behavior of any program through Event Tracing for Windows (ETW). Nothing less, nothing more."
Juglaret concludes: "For Firefox this is particularly impactful because Firefox (not Defender!) relies a lot on VirtualProtect (which is monitored by MsMpEng.exe through ETW). We expect that on all these computers, MsMpEng.exe will consume around 75% less CPU than it did before when it is monitoring Firefox. Which is really good news."
Microsoft's mpengine.dll version 1.1.20200.4 update was released on April 4, and the results have been pleasing according to user reports on Reddit. Juglaret has suggested that more work can be done by the Microsoft and Mozilla development teams in order to improve general performance: "The latest discoveries in bug 1822650 comment 6 suggest that we can go even further down in CPU usage, with all antivirus software this time, not just Windows Defender."
Sources:
TechSpot News, Mozilla Bugzilla Update
Microsoft and Mozilla developers have collaborated on addressing the disharmonious relationship between Defender and Firefox. A plucky member of the latter's softwareengineering team has been very transparent about the sluggish browser experience. Yannis Juglaret has provided a string of project updates via Mozilla's Bugzilla tracking system - one of his latest entries provide details about the fix: "You may read online that Defender was making too many calls to VirtualProtect, and that global CPU usage will now go down by 75% when browsing with Firefox. This is absolutely wrong! The impact of this fix is that on all computers that rely on Microsoft Defender's Real-time Protection feature (which is enabled by default in Windows), MsMpEng.exe will consume much less CPU than before when monitoring the dynamic behavior of any program through Event Tracing for Windows (ETW). Nothing less, nothing more."
25 Comments on Microsoft Fixes Windows Defender Bug After Five Years of Firefox Slowdowns
Yeah trying to kill FF usage
Fortunately I've always disabled pretender oops I mean defender so kudo to third party AV's and of course @W1zzard for his scripts :cool:
www.techpowerup.com/forums/threads/windows-11-tweaks-for-gpu-benchmark.287480/
That said, I was more a FF user until they adopted that space-wasting and not very attractive UI and took away the ability to revert. I know you can adjust it with CSS tweaks, but that’s not going to win them market share from average users.
You have an example of what UI you're referring to because everything looks fine to me frankly.
learn.microsoft.com/en-us/windows-hardware/test/wpt/windows-performance-analyzer
maybe devs should only get to use 200 mhz Octo-core. I bet software would get a lot less bloated and more multithreaded lol
Why with new video card it loses frames on HD60 fps video?
Ahh the days of connecting to the internet and instantly having every PC on the network infected and all write-access network shares decimated...
Sure, those companies mine data. But they're mining far less important data than what they protect - don't use the shittier brands and you're fine.
I use ESET Smart Security. I don't believe any data (besides I guess what's needed for improving the software, and even that is opt-outable) is being mined. If they were, someone would have probably find out by now and it would make it into relevant IT circles.