Firefox engineers discover a Windows Defender bug that causes high CPU usage

Post by tomrod » Wed, Apr 05, 2023, 9:00 PM UTC

fsckboy wrote: post #81

cjblack wrote: post #67

Earlier quoted context omitted.

I'm curious how much excess energy has been consumed, and won't be consumed any longer, as a result of this improvement - even just limited to reduced CPU usage on Windows machines using Firefox to watch Youtube. I love thinking about the impacts of tiny improvements at scale like this, might do some napkin math on it later and see if I can come up with something in the right order of magnitude.

firefox browser share is teeny tiny these days

Post by tomrod » Wed, Apr 05, 2023, 9:03 PM UTC

0000000000100 wrote: post #62

stkdump wrote: post #34

Earlier quoted context omitted.

I've read that a number of times now, but I have trouble matching it to my perceptions. Can you point to a specific website where you notice that slowness and then describe what action is slower? (Initial load, clicking stuff, scrolling, etc.) Just as an example, loading jslinux.org for me in Firefox is about twice as fast than in Chrome. That might be a special case of course, because it is a very special type of wo…

WebGL / Canvas heavy sites are typically significantly slower in Firefox compared to Chrome. Google Maps is a pretty good example of this.

Post by bakugo » Wed, Apr 05, 2023, 9:05 PM UTC

thewataccount wrote: post #56

ravenstine wrote: post #46

Windows Defender is a long standing bug in the Windows operating system. ;) My impression is that its invention was for the sole purpose of eradicating the idea that Windows is insecure and prone to viruses, which explains why it can be overzealous and CPU hungry. I would only enable it for family members who don't know what they are doing. For some reason, I haven't needed any form of active virus scanning in someth…

There's a misconception that you need to do something "stupid" to get a virus which is simply not the case. 0 days exist, and worms are still a thing (looking at you samba). A great example is Pytorch just recently had a supply chain attack, and installing the nightly version between December 25th and December 30th, 2022 - would result in your home directory getting uploaded including ssh keys. Chrome also just had a…

Post by kevingadd » Wed, Apr 05, 2023, 9:07 PM UTC

boringuser2 wrote: post #21

marcodiego wrote: post #13

> a ~75% CPU usage reduction was noted when browsing YouTube in Firefox I wonder how many of the people who say "Firefox is significantly slower than chrome" are using windows... On my computer, Firefox IS slower than chrome but (with ad blockers enabled) by an insignificant amount. By still being "the last remaining mostly independent, maintained and reasonably popular browser" I'd prefer it to use over chrome even…

Firefox is significantly slower than chrome. This usually doesn't matter, but you can immediately see it in any page that A) has a massive DOM or B) uses complex regular expressions that eat up the engine

Post by jldl805 » Wed, Apr 05, 2023, 9:14 PM UTC

ziml77 wrote: post #76

marcodiego wrote: post #13

> a ~75% CPU usage reduction was noted when browsing YouTube in Firefox I wonder how many of the people who say "Firefox is significantly slower than chrome" are using windows... On my computer, Firefox IS slower than chrome but (with ad blockers enabled) by an insignificant amount. By still being "the last remaining mostly independent, maintained and reasonably popular browser" I'd prefer it to use over chrome even…

It's not just Windows that it's worse on though. It doesn't perform well on macOS either. It's not as bad as it used to be when it had a horrible power draining interaction with display scaling on macOS, but it's still isn't as efficient as Chrome or Safari.