If you usually work on Windows and use the browser Firefox You are in luck because Microsoft has just fixed a bug that negatively affected its performance.
The anti-malware service of Microsoft Defender he was acting strangelyshowing high CPU usage when Firefox was running at the time.
Users have been complaining about a excessive CPU usage when Firefox is open, even making it stop responding which has prompted them to use other browsers such as Edge or Chrome.
Last March, it was the Firefox developers themselves who discovered the origin of the problem and thanks to this, Microsoft has finally provided a solution.
The basic problem that we see is the time to hit the key, and the migration that the end user has made to other options that “worked better” during these 5 years.
The source of the problem: Microsoft’s anti-malware system
According to Mozillawhen he ran Firefoxthe Defender MSMpEng.exe service was executing a very high number of calls to the Windows kernel VirtualProtect function while doing Windows Event Tracing (ETW).
This function is in charge of changing the protection of a region of virtual memory addresses during the calling process, to isolate possible threats. According to MicrosoftDefender was doing a lot of useless calculations and generating a lot of ETW events.
This combination caused 5 times more CPU to be consumed than necessary when running Firefox, compared to other browsers. The new version 1.1.20200.2 of the Defender engine fixes this. Can download the update from Windows Update on your Windows computer for free.
In fact, the solution has reached the stable update channel along with the new definitions on April 4. According to calculations by Mozilla developers, you can see a 75% improvement in CPU consumption when using Firefox now.
The update is also available for teams windows 7 and Windows 8.1 since Firefox continues to offer support at least until 2024.
And well, this solution seems to be the beginning to be able to improve consumption even more. Engineers at Mozilla have commented that after all this analysis process will be able to lower CPU consumption with all antivirusnot just Defend.
