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Mozilla Software Bug Communications Open Source

A Pointed Critique of Thunderbird 3's Performance Compared to v.2 234

PerfProtector writes "Did you recently install Thunderbird 3 or upgrade from Thunderbird 2 to Thunderbird 3? Did you notice any severe slowdown in your machine or a major decrease in its performance? Well, many people around the world encountered these problems. We wrote a technical analysis about the severe problems that are caused by Mozilla Thunderbird e-mail client. These problems include anomalous usage of CPU, memory, hard disk and Internet bandwidth. You can read the full analysis, including several graphs that show how bad the situation is and what went wrong from Thunderbird 2 to Thunderbird 3. For example, while CPU utilization of Thunderbird 2 is usually between 0% to 10%, with an average of 0.3%, Thunderbird 3 CPU utilization is between 5% to 80%, with an average of 30% — 100 times more than Thunderbird 2. In addition, during long periods of time, Thunderbird 3 used more than 50% of the overall CPU resources.This behavior slows dramatically the whole machine." It's worth noting that this analysis comes from developers who have developed a (freeware) tool they claim will improve Thunderbird's performance, but they explain also how to do so with manual changes.
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A Pointed Critique of Thunderbird 3's Performance Compared to v.2

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  • Indexing (Score:5, Informative)

    by Capt.DrumkenBum ( 1173011 ) on Thursday August 05, 2010 @02:55PM (#33153260)
    I have not really seen this behavior, but have seen it get stuck doing some kind of indexing forever, or at least until I restart Thunderbird.
    • We wrote a technical analysis about the the severe problems that are caused by Mozilla Thunderbird e-mail client.

      While the the post from yesterday regarding the bettered done was byfar the the biggest slip up of grammar ever seen, this one is mild...

      • Re: (Score:2, Funny)

        by Threni ( 635302 )

        Sounds like it's been written by an Indian. "Please to be ignoring definite article".

    • Re: (Score:3, Informative)

      I noticed that all the indexing was a big drain right away, so disabled it. I do have 4 email accounts, all IMAP, with 10k, 15k, 2k, and 200 messages, respectively.

      • by IANAAC ( 692242 )
        When I first installed v3 I disabled indexing too, with only two IMAP accounts, because it was dog slow.

        And it actually crashed quite a bit for me under Lucid Lynx. I finally gave up on TB and switched to Evolution. That is also quite slow, at least to start up, but things like calendars (Google, tasks (RTM - read only, unfortunately) and memos (Tomboy sync) are much better integrated.

      • Re: (Score:2, Interesting)

        by andyi ( 959526 )
        I definitely noticed this performance hit. I use POP for several accounts, one of which holds over 100,000 emails. Once I archived the bulk of them using Thunderbird's archive, the indexing penalty seemed to disappear completely. Now, I still have access to the archive for searching, but since it doesn't change, there's no new indexing done on it.
    • Switch to Mozilla seaMonkey or Opera and use their internal email clients.

    • I see a different but similar problem: Thunderbird will pretend it's performing some kind of action while actually doing absolutely nothing. Consequently I can't receive any mail until I restart it but there is no indicator (such as heavy load) to tell me when this happened.

      However, it's still rare enough that the proper OS X scrolling support outweighs it.
    • I've noticed that it tends to slow down the system a couple of minutes after I maximize the window if its been left running in the background, and it had nothing to do with it caching to the hard disk or something... not sure whats causing it. Other than that I've seen none of the issues listed in the article...

      (WinXP Sp3, very thin install)

      • There was supposed to be a "for" in there somewhere before someone jumps on it. :P

        and its not a huge slowdown, just barely noticeable.

  • by Ossifer ( 703813 ) on Thursday August 05, 2010 @02:56PM (#33153270)


    Did I notice any slowdown at all?


    Solutions for problems that (to me) don't exist...

    • by AliasMarlowe ( 1042386 ) on Thursday August 05, 2010 @03:46PM (#33153886) Journal
      I also use Thunderbird 3 for 2 pop mailboxes and 1 imap mailbox (with about 8 email addresses in aggregate). No slowdown or resource-hogging has been observed. It appears just as snappy as Thunderbird 2 was, but with a few new features.

      FYI, this is not on a multi-core speed-demon PC. We run Thunderbird on a 7-year-old Pentium-M laptop (Ubuntu 10.04).
    • Re: (Score:3, Interesting)

      by rssrss ( 686344 )

      Me neither. The only thing that bothers me is that it doesn't write new mail in the tabs.

    • by citylivin ( 1250770 ) on Thursday August 05, 2010 @04:05PM (#33154114)

      Well your lucky then. I upgraded to thunderbird 3 half a year ago and had to downgrade back to thunderbird 2. The reasons were exactly the same as the article, all around poor performance, many crashes and problems. I tried some fixes such as disabling indexing, but they only made it bearable. Thunderbird 2 however is rock solid on my quad core machine.

      Do you use both imap and pop? Are you on linux instead of windows? There is probably some way you are using the program that does not reflect the majority. I have heard many reports of people with problems with thunderbird 3 performance. Simply take a look at their forums to get a good sampling.

      • by MSG ( 12810 ) on Thursday August 05, 2010 @05:08PM (#33154820)

        Simply take a look at their forums to get a good sampling.

        Whatever you get from the forums will not be a "good sampling". Users for whom Thunderbird works normally (which I presume to be the majority) will not be posting on the forums.

    • Re: (Score:3, Informative)

      Haven't noticed the issue on OS X 10.6.4 --I wish the same could be said for Firefox though on both OS X and Windows. An interesting note, as I was reading the summary, TB popped-up a dialog that said v3.1.2 was available.
      • Re: (Score:3, Informative)

        by AmiMoJo ( 196126 )

        Have you tried a new profile? Apologies if that seems a bit condescending but it fixes a lot of problems, especially if you have been upgrading from older versions. I had issues with 3.0 which I fixed by making a new profile and copying my bookmarks and a few other bits into it.

        There should really be a big flashing message telling you to do that when you click on the help menu.

    • I have not noticed any slowdown of my computer. In fact I started it up and used control-alt-delete to monitor active processes. When I told thunderbird to get mail(no new mail) I seen it rise from 0 to 1 for about a couple of seconds and fall back to 00 where it is right now. So for me this is not a worthy story and should not even be on /.
  • Limited problems (Score:4, Informative)

    by snd_chaser ( 104514 ) on Thursday August 05, 2010 @03:01PM (#33153346)

    Seems like this only affects

    A) People with very large mailboxes
    B) People using IMAP
    C) A + B

    I haven't encountered any problems with Thunderbird 3.

    • I'm using Thunderbird 3 on Fedora 13 to access my mail over IMAP. I'm not sure how much is "very large" but I have about 11,000 messages in my inbox now, and several folders with a total of probably 100,000 messages. I haven't seen any performance problems compared to Thunderbird 2.
    • Re:Limited problems (Score:4, Informative)

      by Just Some Guy ( 3352 ) <> on Thursday August 05, 2010 @04:11PM (#33154204) Homepage Journal

      Seems like this only affects

      D) Random other factors (maybe whether the profile was upgraded or wiped out and created anew?)
      E) C + D

      I've never voluntarily deleted a single non-spam email that was sent directly to me (eg, I've pruned old mailing list messages, but not stuff in my main inbox). As of this moment, I'm using Thunderbird 3 and IMAP to access 84,000 emails taking about 2GB on the server. It's still fast and responsive, and uses few resources while idle.

    • i've gigs in my inbox (and i dont have 1000 dirs, just 2 with gigs in it) and i use imap and i don't notice any slow down. That said if they found a bug I'm all for them reporting it, but it doesn't looke like it.

    • I'm a C and it doesn't affect me.

      I use TB 3.1.1 with three Gmail IMAP accounts, one of them huge with messages sorted into over 100 folders and I don't experience the issues TFA rants about.

      My bugbear is that the Message Synchronization feature *doesn't* work, even though it's enabled and every single folder has Download ticked - regularly I'll change into a folder for a given task and have to wait for TB to download messages that I dragged into it hours, days or weeks earlier.

      • by Lennie ( 16154 )

        Yes, I've seen that too. I expected it to download new messages from a folder, but when you change to it, it will not have collected the new messages, but TB will automatically check for that folder and finds some.

  • Yes, storing and providing full text search over a large pile of email consumes resources ... duuuh?

    Also they're measuring the performance of Thunderbird while converting to the new system, not in its steady state. This is like complaining that Firefox uses a lot more CPU importing settings from IE than IE uses when looking at your home page.

    Their claim as to how long it took to do the full text indexing of the mail seems dubious to me. I've got a similar amount of mail, and the time it took to index was more like minutes, not days.

    • Re: (Score:3, Interesting)

      by N7DR ( 536428 )

      Their claim as to how long it took to do the full text indexing of the mail seems dubious to me. I've got a similar amount of mail, and the time it took to index was more like minutes, not days.

      Must be a YMMV thing. After four days of waiting for 30 seconds or more at a time just to do simple things [and even longer just to exit the program; the OS kept inviting me to kill the program since it didn't actually close sufficiently quickly -- every time I exited; that got real old real quickly], I turned off all the indexing. I kept hoping that it would finally finish indexing, but there was no indication here that it was ever going to do so. It seemed (here... again, YMMV) that simply receiving a new

  • I also noticed no slowdown, and I get pretty heavy e-mail traffic. Still if that many people are affected, I expect a patch soon.
  • In my humble experience, Thunderbird 2 was all ready much slower than Outlook Express (the switch was reversed after two weeks). Sounds like I'll be stuck with OE for a while longer.
  • Summary Fail (Score:5, Informative)

    by The MAZZTer ( 911996 ) <<megazzt> <at> <>> on Thursday August 05, 2010 @03:12PM (#33153470) Homepage

    Would be nice to mention that the increases are due to use of search indexing and/or IMAP account synchronization (especially with a large amount of e-mail). They don't do a comparison of what happens when you turn those off which I think would be more useful.

    On a side note I was bored with the apparently stagnation of Thunderbird (I couldn't even find a good Aero Glass extension that worked during the 3.1 beta) I tried Windows Live Mail. It was interesting up until the point where it refused to show any mail from one of my accounts and insisted it wasn't failing. At least Thunderbird actually worked...

    Switched one of my machines to Linux and am using Evolution which is actually quite nice... the account setup was far more pleasant and simple than Thunderbird or WLM and both my accounts worked fine.

  • Long ago, in the days of Netscape 6/7/8, the mail client of what was later Mozilla Suite (now SeaMonkey) was absolutely fantastic in terms of performance. The "new" standalone Thunderbird as introduced was horribly slow by comparison, and has only gotten substantially slower over time, even on the same hardware with roughly the same level and rate of messages. I haven't tried SeaMonkey recently, but several years ago it seemed an order of magnitude faster than Thunderbird. Does anybody know how Mozilla m
  • by ArsonSmith ( 13997 ) on Thursday August 05, 2010 @03:28PM (#33153642) Journal

    This is why all software you use must be open source, this wouldn't happen if people were able to get in and see the code that is actually causing the problems

    • I find funny rated comments funny but I found this one fun enough that i'm replying just to say so!
      Or maybe it's the alcohol, who knows.

      In any case thanks for the laugh lol

  • by WolfWithoutAClause ( 162946 ) on Thursday August 05, 2010 @03:33PM (#33153700) Homepage

    It can go into orbit!

    Thunderbird 2 is heavy and can only go supersonic!

    There's no contest! What planet are you guys on?

    Link: []

    • Re: (Score:3, Funny)

      by rossdee ( 243626 )

      Actually I remember reading a 21st Century comic that had T2's engines getting stuck on full throttle, and it went into orbit, and they had to send T3 after it.

      But I also remember that the top speed of T2 was quoted as 5000 mph (cf T1 top speed of 15000 mph) both presumably in the atmosphere)
      I don't think Gerry Anderson ever did any wind tunnel tests on his models...

    • Yes, but it's Thunderbird 2 that you need to get the rescue gear to site. And I'm relieved that I'm the only one that read the headline that way.
  • by Anonymous Coward

    Thunderbird 2 is a heavy lift loader VTOL craft with a large payload bay.
    Thunderbird 3 is an orbit capable single stage rocket that could land in its vertical takeoff position.\ []

    somebody had to do it.

  • The graphs are nice, but they don't tell the whole story.

    What builds?

    I have noticed severe memory leaks with Mozilla apps not at stable release level.

    TFA by 'Perf Protector' says 'a beta tester' is providing the data - from an 'infected' Windows machine, apparently in a corporate environment.

    Coincidentally(?) 'Perf Protector' is the tool used to generate the graphs as well as the handle of the poster. Is this a soft anti-Mozilla Slashvertisement for a Windows performance monitoring tool?

  • Seriously, they require your computer to go everywhere you do. Web email is the way to go.

    Plus all the thunderbird users are annoying because they send messages every coupe years about their email changing because they changed ISPs.

    One web-based email account fan fix all that.

    If your internet is out -either at the provider or your house, then what good is email anyway?

  • I've been a devotee of Tbird ever since I junked Evolution because it spent too much time housekeeping and it appeared to open and load every folder of every mailbox every time it started. I wanted a mailer that would only open a folder when I clicked on it.

    Now Tbird (3) seems to spend all its time indexing something. I have no idea why — I didn't ask it to, and it's slowing down the whole operation, whatever about its use of memory and other problems.

    It has certainly slowed down, and sometimes wh

  • Anybody else think this was a story about Thunderbird 3 [] vs Thunderbird 2? []
  • Duh? (Score:5, Informative)

    by tomz16 ( 992375 ) on Thursday August 05, 2010 @03:47PM (#33153892)

    The two proposed changes in the article are to :
    - disable the global indexer
    - disable caching of messages to the local computer

    It should come as no surprise that these two features increase cpu load and bandwidth consumption respectively...

    • Re:Duh? (Score:4, Interesting)

      by DerPflanz ( 525793 ) <> on Thursday August 05, 2010 @03:57PM (#33154036) Homepage

      The two proposed changes in the article are to :
      - disable the global indexer
      - disable caching of messages to the local computer

      I consider it a design flaw that these two settings are on by default, also for IMAP folders. The whole point of IMAP folders is to keep your email on the server. I don't want to download 4+ years worth of e-mail to my computer. I had the same problems and immediately switch these two options off on any new installations.

      I found this already on May 5th []. Didn't know about the options though. I ditched version 3 for 2 for a short perios of time afterwards.

    • by Trepidity ( 597 )

      In addition, they didn't do any of the benchmarks on which Thunderbird 3 is much faster as a result. For example, in Thunderbird 2, it takes forever to do a full-text search of an IMAP inbox. In Thunderbird 3 it's nearly instant.

  • I was one of the last of my friends to give up the desktop mail client. I was an email packrat and kept everything, archiving off messages once in a while. I have archives going back to 1995 using the predecessor to MS Outlook and the earliest Netscape offerings. But once I moved my domain mx record to Google mail a couple years ago I dumped the clients and haven't looked back. I've felt completely liberated ever since. Using one IMAP mailbox accessible from browsers and mobile apps anywhere is the way

    • I use a thick IMAP client for my Google Apps-powered e-mail account on my desktop, and generally stick to Gmail on whatever portable I've got at the time. While I do have a couple peeves with Gmail's IMAP support, it's worked out quite well. I, too, thought offline reading might be an issue, but seeing as my thick client – Thunderbird, as it happens – keeps an offline copy of everything, it's yet to prove a problem.

  • I use Thunderbird 3.1.2 with a pair of IMAP accounts. I've noticed the following:

    1. The Archive folders shouldn't have "unread" messages in them. This causes strange bugs where Thunderbird shows messages in Archives on the new message list when I receive additional email, despite me having already viewed the copy of the same message in my Inbox.
    2. Since 3.1, Thunderbird randomly stops responding. It's literally unusable for 15-20 seconds chunks, sometimes longer. Sometimes when I'm switching messages in

  • I saw thunderbird 3 go crazy and keep redownloading and indexing the same messages from an imap server over and over and over until it turned a couple hundred MB of email into 34GB and completely filled the user's hard drive. The only thing that stopped it was to remove the program and delete the profile. No problems with thunderbird 2 or outlook on the same imap server. Thunderbird 3 while it has nice features has some serious bugs. Be warned!
  • There is most definitely a performance problem and resource abuse issue with Thunderbird 3. The Portable version can't even run correctly at all from any but the fastest external Flash/SSD media, instead it must be run from an external HDD; otherwise the user interface takes extended sabbaticals for ten seconds at a time when even the mouse is ignored. It isn't simply the indexing feature, because explicitly disabling it in the configuration did nothing to relieve the above symptoms. I can't claim to kno

  • Mork (Score:5, Interesting)

    by bill_mcgonigle ( 4333 ) * on Thursday August 05, 2010 @04:19PM (#33154292) Homepage Journal

    The problem is Mork. It's a stupid old database that Mozilla products are saddled with. When you have a big one, the whole damn thing needs to be loaded into memory to be parsed. Big folder? Bam, there goes a hundred megs of RAM. Swap if needed.

    Replacing Mork with sqlite started a long time ago, has achieved limited success in some Mozilla products, and has been effectively abandoned in Thunderbird.

    All this burns tremendously more computing resources than are really needed. Why does Mozilla hate the environment?

    • Re:Mork (Score:5, Interesting)

      by Animats ( 122034 ) on Thursday August 05, 2010 @05:26PM (#33155034) Homepage

      Classic mistake - writing your own database. This was a long-standing vice in the UNIX world, BIND and Sendmail being the classic offenders. for a long time, Windows had an edge - Jet, which is a little database engine used by applications. The open software world now has sqlite, although it's not used well in Firefox.

      At one point I was trying to explain that a problem they had with duplicate entries in the password database should be fixed by making one field a unique key. "But that would break programs", was the objection. It would break the ones that were inserting bogus data, yes. The solution implemented was a JavaScript kludge that tried to fix the database when Firefox exited, which was O(N^2) at least and could hang Firefox on exiting. So the solution to that was to tell users to get rid of unneeded password entries. Some developers just have no clue about how to use databases.

      SQLite isn't a bad database, provided you don't need to do many concurrent updates. (It can handle concurrent updates correctly, but the locking works by polling and retrying a file lock, which is painfully slow. So don't use it to run your web site. Get MySQL or Postgres,) Given what Firefox does, it really should keep its messages in SQLite databases, not "folders".

    • Replacing Mork with sqlite started a long time ago, has achieved limited success in some Mozilla products, and has been effectively abandoned in Thunderbird.

      You sure about that? I have a big fat file named global-messages-db.sqlite in my Thunderbird profile, and it contains the text of my messages among other things (e.g. I can do select * from messagesText_content). It still seems to update the MSF files as well though.

  • I have actually found the opposite, Thunderbird 2.x in OS X was dog slow and prone to random periods of non-responsiveness. Thunderbird 3.x on the other hand has been quite snappy.

  • sylpheed is better: []

    it uses MH for storage (similar to maildir - a requested tbird enhancement that has fallen on deaf ears for years)

  • I run thunderbird, and disabled the indexer a while back. But, calling 3.x buggy crap and not 2.x is a bit misleading. I had the distinctly icky experience of trying to find a strange IMAP crash back a few years ago.

    I should have immediately given up, when my debug build failed to even run, poping on assertions all over the code base. The whole IMAP implementation in thunderbird is (was?) such a mess its lucky to be working. I remember finding bug after bug, and comment after comment about "hacks" made to a

    • I found TB2 slow and buggy compared to TB3 to be honest. For me it's been a relief. I'm not happy with everything in TB3 but I haven't found better and it's still pretty good overall.

  • by steveha ( 103154 ) on Thursday August 05, 2010 @04:41PM (#33154526) Homepage

    At work, I have a Windows machine I need to use. I installed Thunderbird on it to read my personal email.

    One day, Thunderbird offered me an update to Thunderbird 3. Sure, why not; I let it upgrade.

    So, the next day I got an urgent email from the corporate IT department demanding to know why the corporate antivirus was reporting dozens of viruses on my work computer! I was not pleased.

    My email server has a virus scanner (ClamAV of course), and when it detects a virus, it shunts the virus email message into a special folder. I rarely look at the folder or worry about it. Well, Thunderbird 3 changed the default behavior without asking me anything, and downloaded every message in every folder I have. Not just headers, message bodies as well. Thus, it downloaded a bunch of virus emails onto the hard disk of my corporate Windows desktop computer.

    Long story short, IT ordered me to uninstall Thunderbird to make sure that this could never happen again. (IT recognizes that the viruses were never active on my system, but they officially have a zero-tolerance policy about viruses being present inside the corporate network at all.)

    So I am no longer a Thunderbird user. I found another way to read my personal email while at work.

    I was always happy with the old policy, of downloading message headers only, and grabbing the message bodies when I actually opened an email to read it. The new policy might make sense if I had a single machine that I always used to read email and I always wanted my email stuff to be as fast as possible (everything cached to the local hard disk). But I use IMAP and I read my mail from a half-dozen different computers, and the vast majority of my email on my server is old stuff I rarely look at. The new policy of downloading everything makes no sense for me, and I didn't see any way to globally change the setting; it looked to me like you need to change the setting on a folder-by-folder basis. (I could be wrong about that, but it doesn't matter because I had to abandon Thunderbird anyway.)

    I don't think defaulting to downloading the entirety of every message on a server is a good idea. And it led to me being forced to abandon Thunderbird, so Thunderbird has at least one fewer user as a result.


  • E's bleedin' demised!

    At this point I could not care less what's up with TBird. TB3 was so badly mangled that after years of using TB, their 'latest greatest' convinced me to I give up and (ugh) switch to Apple Mail. It's the only Apple app I use routinely, which should say something about how much of an albatross TB3 has become.

  • by bl8n8r ( 649187 ) on Thursday August 05, 2010 @05:01PM (#33154748)

    Thunderbird 3 builds indexes of your mail boxes for every account. If you have huge mailboxes, the indexer is going to need some time to look through it all. You can turn off the indexing if you want through the advanced config editor (global search and indexing)[0].

    "By default, Gloda indexing is enabled [93], also for migrating accounts. Note that indexing a large amount of e-mails takes considerable time and resources, especially when setting up a new account or migrating from an old profile! " [1]

    [0] - []
    [1] - []

  • Thunderbird 2 had a clear, easy-to-use interface, with quick and simple searching and a nice layout. Thunderbird 3 doesn't appear to have a search function - although you can tell it to search, what it does is open up a new tab with all the emails that have anything in the search term in them, or sometimes nothing from the search terms which are presumably included just for fun, or because they looked lonely.

    The best bit is when you try to find out if it's possible to disable tabs - you can't! The response

  • Thunderbird 3 hangs up regularly on my Macbook Pro (stays open, but does not respond to keyboard/mouse interaction). I rarely reboot my computer, and usually I have to kill the process 5 or 6 times per day to get my emails. One thing I've noticed is that if I do not quit Thunderbird before closing the lid of the notebook, when I open it is no longer responding. I do not care much about all the new bells and whistles, but need a reliable mail program that uses some sort of standard storage format, and allow
  • I used tbird for over a year, and when I was laid off, and had to send out email that looked nice, and needed a good online calendar, I found that tbird didn't work for me. it wasn't performance, it was features; for 40 bucks, you can get a copy of office 2003 off of ebay, and outlook has a lot more formatting features then tbird not to mention the calendar; the calendar on tbird basically sucks bigtime etc YMMV; I just don't get why you would use tbird if you have the 40 bucks; I'm sure there are a lot peo

Air is water with holes in it.