Version: (using KDE KDE 3.5.2) Installed from: Gentoo Packages Compiler: gcc-3.4.6 OS: Linux The same as bug 69439 from 2003: "Switching from one mail folder to another, where the destination folder has in excess of 10,000 messages (all folders are Maildir) causes a long pause (more than 10 seconds) and kmail is unresponsive for the duration of the swich. The more messages you have in the folder, the longer the pause." I have 2 different maildir folders on a local ext3 filesystem, about 55000 mails each. It takes 25 (twenty-five) seconds switching to one of these folders, everytime. Afterwards I switch back and forth, the same thing. Processor activity rises to 100% until switching is finished. Hard disk activity is 0, so this might not be a filesystem issue. My machine is a 1600/3000+ AMD Sempron (AMD64), 1 GB of RAM (533 MHz dual channel). This should be enough. My last machine (1200 AMD Duron!, also ext3) used an older version of KDE (I think 3.4). That old system was a lot faster in switching to the same folders. Christian
Do you use message threading? If yes, does it help to turn it off completely? Does it help to turn only threading by subject off?
My configuration: General Options [ ] Threaded message list" Threaded Message List Options [X] Open threads that contain new, unread or important messages and open watched threads." These were the default settings since starting KMail 1.9.1 for the first time. The first is unchecked (turned off), the second is checked (turned on). I turned off the "Open threads ..." option by selecting "Threads default to closed" and it's much faster since then. (Thanks for the hint! :-) This seems to lead to another unexpected (at least for me ;-) reason: It seems that some options in the "Message List" tab have no effect when changing. "Threaded messages list" seems to be activated, but it's not checked. (See above) I also checked "Display message sizes" (because I missed them in the message list today), but it has no effect. Even after restarting KMail I cannot see any sizes (yes, I noticed the scroll bar at the bottom). Should I open a new bug report for this? Christian
The general setting "Threaded message list" can be overridden by the folder specific setting which you can find in the Folder menu. IIRC then there's already a bug report about "Display message sizes". As workaround try right-clicking on the message list header and then enabling the Size column.
FWIW, I just made a quick test. Switching from a folder with a small number of messages (e.g. the outbox) to my kde-devel folder with about 45,000 messages took about 20 seconds the first time and about 10 seconds the next time. And I'm using my good old Athlon 550 and for the kde-devel folder threading and threading by subject are both enabled and "Open threads that contain ..." is also enabled. Weird.
Ok, as I mentioned before "threads default to closed" works: Switching to large folders takes about 1 seconds. That will do for me. (Thanks again for the hint! :-) But maybe for others who read high traffic mailing lists and want to have some threading options enabled, these options are not fast enough. Unfortunately I cannot provide really safe info about this problem because some options don't seem to work on my KDE installation (see my older mails above), so that I cannot be *sure* which options are turned activated and which are not. I will add another bug report about this because I didn't find it in the bug db. What I can provide to this "speed problem" is the following: ***** [X] Always keep threads open: [ ] Open threads that contain new, unread or important messages and open watched threads. Switching to a folder with >55000 mails for the first time: 28 seconds. Switch back and forth to the same folder: about 1 second. I think that's ok. ***** ***** [ ] Always keep threads open: [X] Open threads that contain new, unread or important messages and open watched threads. Switching to a folder with >55000 mails for the first time: 25 seconds. Switch back and forth to the same folder: 25 seconds. To be more precise: It *always* takes 25 seconds to open this folder with this option. KDE 3.5.2, KMail 1.9.1. ***** Christian
I can confirm this slow switching bug. The system is an Athlon 64 3200+, dual channel 1GB memory, so not exactly a slow one: Switch from inbox (1000messages) to kde-core-devel(21000 messages): 4 seconds switching back is < 1 seconds. Switching a second time gives me no noticeable difference. Switching to a folder with 12500 messages is about 2 seconds. This is with Thread Messages and Thread also by subject enabled. With them disabled it takes about 3 seconds to switch to the 21000 messages folder. KMail and KDE from around 3.5.6 was tagged.
See also bug 88467, which might be the same issue.
Kmail trunk is even worse. A folder with 7500 messages from which 2500 unread is unusable (dual core, 2GB memory). Not only the switching, but anything in there (reading, scrolling, etc.). Another one with 14000 messages, all read is also slow, but at least usable.
András, for the speed problems in trunk/KDE4, see 163469.
Hi. Is this bug still valid? With the new messages list it is much faster.
Partly. It is faster, but more annoying. Switching to my kde-commit folder which currently has 7280 messages, 1720 unread is instant, but for 8-9 seconds the message list keep reorganizing itself, it is basically unusable, you scroll somewhere and it scrolls away.
I have to say the problem is probably because of the high number of unread messages, switching to another folder that has 15000+ and only 10 unread works just fine.
> I have to say the problem is probably because of the high number of unread messages, switching to another folder that has 15000+ and only 10 unread works just fine. That could well be, because unread messages in threads are expanded automatically, and Qt4 is dead slow when it comes to expanding/collapsing something.
So is this in the end just about qt slow expanding of listitems?
*** Bug 233134 has been marked as a duplicate of this bug. ***
If it helps, it seems that after you disable the auto opening of threads with unread messages, and tell it to only show unread threads, then tell it to expand all threads, its speedy. Could be a hint to whoever eventually looks into fixing this. Though I have to say, switching into a maildir mailbox with 100k+ messages is STILL pretty slow (not as bad as it was) even with auto opening unread threads turned off. So I'm not sure the entire cause is Qt's slowness when expanding listitems.
I can confirm this problem is still there in kde-4.3.2. Opening an IMAP folder (local net) with 35000 messages where most of them are unread in the "Threaded date view" mode takes 2 minutes reorganizing the message list each time before I can scroll somewhere and actually use the folder. This bug has been with us for so long now, any chance this will be fixed one day? It is one of the primary reasons kmail is mostly unusable with large folders in thread mode, isn't this supposed to be bad enough for kmail developers to really worry? I realize this fix isn't trivial, but if QT is at fault, what about trying to fix Qt or at least implement a work-around for this problem? IMHO, not using threaded view in large mailing-lists is not very useful! In the worst case, it Qt's tree widget is not scalable for such use-cases, maybe KDE needs an alternative widget for tree-lists? Come on, it has been 7 years now! Please start doing something!
Thank you for taking the time to file a bug report. KMail2 was released in 2011, and the entire code base went through significant changes. We are currently in the process of porting to Qt5 and KF5. It is unlikely that these bugs are still valid in KMail2. We welcome you to try out KMail 2 with the KDE 4.14 release and give your feedback.