I use Firefox about 80% of the time. I use Chrome for a few sites I need for work that still use Flash.
I really don't notice this performance issue. I don't use Slack, but do use Google Maps, Google Drive/Docs/Sheets and Gmail and it's all just fine in Firefox from my perspective.
I tend to not keep large numbers of tabs open (just habit more than anything) so that may be part of it. E.g. 10 tabs would be a lot for me.
I also don't sync settings. In fact I have no settings: I have firefox set to basically dump everything (cache, history) upon exit.
It's been my experience over the past couple of years dealing with ugly web-apps that abuse JS, have huge DOMs, thousands of tiny images etc., that such abominations (hacks) will run reasonably well on Chrome while verging on unusable in Firefox. This is from someone who was ideologically wedded to Mozilla for years, and more or less refused to use IE regardless of how good it got; I switch to Chrome basically solely on the basis of performance; secondarily the strength of dev tools and the impressive security model.
It's freaking sad that Firefox is stumbling out multi-process in 2016. This has plainly been the way to go for years. Multithreading is a disaster, it's just not a workable model for browser-scale applications.
But hey, if they could recover Firefox from the ashes of the bloated disaster that Mozilla Suite became, I have hope that the community can catch up eventually. Maybe.
Ok, you got me. What I said was nonsense, taken literally, I was being lazy; you're right, Chrome's heavily multithreaded too. But, there is process-level separation both between tabs/browser contexts with information of differing security sensitivity, and between nasty stuff like parsing and rendering versus basic UI etc. All the good defense-in-depth sandboxing that others have alluded to, that is the stuff of many papers.
FF performance seems to vary greatly per platform. It's nearly on-par with Chrome on Windows and good video drivers, but on Linux with crap drivers, or on an OSX laptop, it's pretty slow.
I use Firefox about 80% of the time. I use Chrome for a few sites I need for work that still use Flash.
I really don't notice this performance issue. I don't use Slack, but do use Google Maps, Google Drive/Docs/Sheets and Gmail and it's all just fine in Firefox from my perspective.
I tend to not keep large numbers of tabs open (just habit more than anything) so that may be part of it. E.g. 10 tabs would be a lot for me.
I also don't sync settings. In fact I have no settings: I have firefox set to basically dump everything (cache, history) upon exit.