Very slow Calendar when starting and refreshing
I have 8 local calendars set up (2 of them actually busy) in my TB 91.7.0 and earlier versions on a Windows 10 and two Debian systems. All calendars are CalDAV calendars with events going back several years and they are stored on a server (radicale) running locally on each of the machines.
The problem is TB's Calendar is incredibly slow. When TB starts it takes a few minutes until it starts showing the first few calendars and around five minutes until all calendars are displayed. When this happens CPU utilisation goes up to 50% and the fan switches on on an i7 machine. On the much slower machine CPU utilisation goes up to 150% for much longer, and everything else practically freezes. Once this process is completed utilisation drops to near 0% as it should. When it refreshes every 30 minutes, the whole process starts again. It's as if TB re-downloads every single event when starting up and refreshing rather than keeping its own database. Also, when a reminder is displayed and I OK it, any events listed in the pop-up disappear but the blank pop-up stays on for several minutes. Even copying/pasting events or redrawing them on screen is slow. Is that normal behaviour?
All Replies (5)
This bug perhaps? https://bugzilla.mozilla.org/show_bug.cgi?id=1224249
@Matt, this is close but they are saying 'The time is consumed before any UI gets visible'. I do actually see the UI as it is being gradually and slowly populated. To eliminate the possibility that my server is responsible, I installed Morgen which works as expected: lightning fast in reading all 8 calendars first and every time. After the initial run, it clearly feels like it has the calendars cached. TB looks like it re-downloads the 1000s of events every time it starts or refreshes. Even drawing is done slowly. I think I will reluctantly have to stick with Morgen until TB is fixed.
I would encourage you to file a bug. This is not something that will be fixed by accident I don't think. There are random reports going back years that really have never been followed up.
The roadmap for The 102 release which is imminent (V99 beta is released) does not explicitly contain anything that looks to performance. https://developer.thunderbird.net/planning/roadmap
Good idea. It's just that I am surprised that with so many people using TB, this is not common knowledge. The separate Lightning add-on was for me impossible to work with. Performance improved with the integrated calendar but the calendar function is still very slow for what it does. I will file a bug even though I see a similar one has been there unresolved for 12 years. Thanks.
I'd humbly suggest that your issue is very likely already reported, unless it only started happening recently.
As for lack of progress - given that there hasn't been a full time calendar developer in over a year, it's not surprising that great progress has not been made. Because most of the gains to be made require rearchitecting, which don't happen quickly. That will soon begin to change, but as Matt indicates, not likely to be addressed in the initial shipping of the next release.