software, windows

Why Outlook 2007 is slow: Microsoft’s official answer

158 Comments

A knowledgebase article published last week acknowledges performance problems with Outlook 2007, though it says these only occur with mailboxes larger than 2GB:

You may experience one or more of the following performance problems when you are working with items in a large Personal Folder file (.pst) or in a large Offline Folder file (.ost) in Microsoft Office Outlook 2007 … Note When you perform the same operations on the large .pst or .ost file in earlier versions of Outlook, the same performance problems do not occur. These problems may occur if the .pst or .ost file is larger than 2 GB. Additionally, the performance problems are more pronounced when the .pst or .ost file is larger than 4 GB.

I think this is optimistic and that smaller mailboxes are slower too; nevertheless, it does confirm that that the size of the local store is the key issue.

If you use Exchange, the local store is the .PST or .OST file on your workstation or laptop. If you do not use Exchange, a local .PST store is all you have.

Here’s what Microsoft says is the reason:

To accommodate new features, Outlook 2007 introduced a new data structure for .pst and .ost files. In this new data structure, the frequency of writing data to the hard disk increases as the number of items in the .pst or .ost files increases.

Intriguing, especially as I had thought the .pst format was the same in Outlook 2003 and 2007. The big change was from Outlook 2000 to Outlook 2003, when Unicode was introduced and the maximum size increased to 20GB.

I’d also like to know whether Microsoft is just stating the obvious here (bigger file, more disk access); or whether there is some exponential increase in disk writes, suggesting a design fault in the software. I have already noticed that if you show the I/O columns in Task Manager’s performance tab, Outlook 2007 shows some extraordinarily large numbers.

So what’s the fix? The news is not too good. In essence, you have to reduce the size of the local store. You can archive or move items to separate .pst files, or switch off cached mode so you always work online to Exchange.

The article doesn’t say it, but there are significant problems with switching off cached mode. These include hugely increased network traffic, problems with junk mail filtering, and loss of all your mail when using a laptop disconnected from the network.

The most imaginative suggestion is to filter the sychronization. For example, you could filter out messagse with large attachments, or all messages from last year or earlier. These messages will still exist in Exchange, but not in the local store.

Worth a try, but none of the workarounds is really satisfactory. Outlook 2003 worked fine with large mailboxes, Outlook 2007 does not. That’s a blunder.

 

158 thoughts on “Why Outlook 2007 is slow: Microsoft’s official answer”

  1. Could this be add-in related?

    This is what I suspected first. But I’m using only one addin (OsaSync Pro) and it is installed on all the systems using Outlook 2007. So I should see the problem on these systems too.

  2. The Microsoft Windows Vista OS enables the TCP Window Scaling option by default (previous Windows OSes had this option disabled). The TCP Window Scaling option is described in RFC 1323 (TCP Extensions for High Performance), and allows for the device to advertise a receive window larger than 65 K than TCP originally specified. This is useful in the higher speed networks of today, where more data can be outstanding on the wire before it is acknowledged. This slow performance, or dropped TCP connections is caused by some versions of Cisco IOS® Firewall software not supporting the TCP Window Scaling option. This causes it to have a much smaller TCP window than the endpoints actually have. This causes the Cisco IOS router that runs the IOS Firewall feature set to drop packets that it believes are outside the TCP window, but which really are not.

    So, through many firewalls, many protocals fall apart.

    And here is a solution, that worked perfectly for me, and several of my clients clients.

    Drop to a command prompt and run:
    netsh interface tcp set global autotuninglevel=disabled

    If the command returns this response, “Set global command failed on
    IPv4 The requested operation requires elevation”, then you need to do
    this:
    Click start (windows symbol), Accessories, right click on “Command
    Prompt”, then choose “Run as Administrator”, then try the netsh
    command (above) again.

  3. Glad I read this, stopped me from smashing my Sony laptop and blaming everything else except Outlook 🙂 I see this on 1 laptop with a centrino, a desktop with a dual core and a desktop with a P4, so go figure.

  4. Hi Tim,
    Am on Outlook 2007 with XP. I have noticed that the performance issues correlate to a sharp increase in Avg Disk Queue length. You can see in Perfmon.exe. I don’t know whether this gives you any ideas..
    Paddy

  6. I’m running Outlook 2007 from my laptop and my main pc. My pst file is set up on a external drive and is about 400MB. The main pc accessing the pst is painfully slow…..but my laptop, which I only use to read and NOT download mail and therefore do not have it set to see my pst file is also painfully slow.
    If Microsoft say this is down to large pst files how do they explain that!!. Both pc and laptop have 1GB RAM – laptop 1.8MHz and pc 3.4MHz and both are duo core….so not exactly dinosaurs. Come on Microsoft – pull your finger out now!!

  7. I too find OL’07 painfully slow, but not much slower than OL’03. Having tried changing bits of the system since installing OL’07 three months ago, it seems to me aside from OL’07 being big, 1) part of the sluggishness is receiving mail from 7 POP3 accounts simultaneously, 2) part of it is having 700K e-mails in 14 PSTs totalling 15G, 3) part of it is my (admittedly effective) CA (whitelist-based) Anti-Spam add-in, and 4) part of it seems to be WDS (I deeply miss Lookout’s “don’t index except at night,” even if it meant searches might fail to include “today’s” e-mail).

    I secured marginal performance improvements by a) doing a clean uninstall of Office (using Windows Install Cleanup and deleting corresponding c:Program FilesMicrosoft Office files and registry keys), then reinstalling; b) running OLFix; and c) running SCANPST.EXE on and compressing my default PST from time to time. Am about to upgrade to a notebook with 7200rpm HDD, which I hope will help if the problem is the HDD accesses. Hard to imagine what else to do.

    I also have, several times a day, OL’07 suddenly be unable to read the default PST file (“Cannot display the folder. ‘Microsoft Windows Operating System’ exited without properly closing your Outlook data file ‘xxx.PST’. ‘Microsoft Office Outlook’ must be restarted. If this error message recurs, contact support for ‘Microsoft Windows Operating System’ for assistance.”); , requiring an exit & restart (and sometimes OL’07 doesn’t quit and requires a Task Manager “end process”–perhaps a side-effect of WDS, I’m not sure). (I’ve exchanged a dozen e-mails with MS tech support on this count, so far with no resolution in sight.)

    I haven’t noticed OL’07 ever taking more than about 85M of RAM on my 1.3G notebook; it does sometimes take up to 65% of the CPU but haven’t noticed the severe processor hogging others have noted.

  8. Thank you dirk! post #10
    dell M1210 vista outlook slow
    Uninstalling Media Direct did the trick!!!!!

    -thad (San Jose)

  9. Please look at item 27 from Bazza.

    If you have a Cisco router (very likely in larger corp) or you have one of their 800 series routers (likely if you have a static IP on a DSL line). then run his fix.

    Speed improved 1000%

  10. Yes

    yes

    yes

    yes!!!!!!!!!!!!!!

    This disgustingly slow Outlook 2007 has had me pulling my hair out for days looking at every post and forum out on the web. Running across Thad’s confirmation #33 on trying Dirk’s solution #10 sped up my OL2007 10000%. I may just start liking it again. Good luck to everyone else that doesn’t have a Dell and Media Direct to uninstall!!

  11. I had problems with OLK 2007 when running VirusScan 8.5 from McAfee. I eventually binned version 8.5 and went back to version 8.0 and things are much better.

  12. Hi, I just had to buy a new computer and it came with Vista. My company uses Outlook 2003 and I have had sooooo many troubles with my email! The send and receive loops around for hours at a time. The progress screen tells me I am receiving 20 emails but won’t send them to me for hours- then suddendly they come pouring in. Most of the day my emails stay in my outbox for 10 min – 3 hours +!!! If I have more than one email in the outbox it’s worse. I usually send and receive 2-3 MB files- everyone else doesn’t have any problems with them… I have spent most of my first 2 weeks on this job on the phone with our IT guy. We have talked to at least 10 different people at Microsoft about whether it is an Internet Explorer issue, or Microsoft Office, or our server or what. I am no longer using IE, and we were talking to comcast today, so I think it might be an outlook/ vista problem. Has anyone else experience similiar issues?

  14. I work on the Outlook team at Microsoft and I read your post discussing the performance issues you’ve seen in Outlook 2007. I wanted to let you know that we’ve released an update designed to improve performance in Outlook 2007, especially for large mail stores. You can read more details about the update in this blog: http://blogs.msdn.com/willkennedy/ but here is a direct link to the download: http://www.microsoft.com/downloads/details.aspx?familyid=C262BCFD-1E09-49B6-9003-C4C47539DF66&displaylang=en . Thanks for your support.

  15. I work on the Outlook team at Microsoft and I read your post discussing the performance issues you’ve seen in Outlook 2007. I wanted to let you know that we’ve released an update

    Ellen,

    Thanks for coming here and commenting. I know the patch is greatly appreciated; on the other hand, I still find Outlook 2007 slower than Outlook 2003. Or should we delete and rebuild our stores to benefit fully from the changes?

    I also wonder why shutting down Windows while Outlook is still being indexed invariably corrupts the store. It’s hard to avoid this scenario unless your PC is always on, since building the index for a large store takes a very long time.

    See here for further comment on the patch:

    http://www.itwriting.com/blog/?p=185

    Thanks again for your comments.

    Tim

  16. Just wanted to say thanks to Dirk as well – I just purchased a DELL XPS1210 and have had it for only 2 days and was going to kill someone with how slow my new Outlook 2007 was. I also uninstalled Media Direct (never got a chance to see what it was all about so now I guess I’ll never miss it) and now my Outlook is running great. I’m not sure if programs like this are causing glitches on other computers but it might be something to check into.

    Mel

  17. DELL M1210 VISTA OUTLOOK PERFORMANCE SLOW
    ( this is a header so you might GOOGLE/Live Search this easier)

    It has been 2 month now since I deleted Media Direct and life has been grand. #33 I do not confess life on vista has been without incident. I still get the infamous blue screen from time to time. (I am still waiting for Apple to make a commercial about that. Perhaps throwing a bucket of Blue paint on the “PC GUY” when he is in the middle of a conversation with the “MAC Guy”) back to the point…… Since I deleted Media Direct fronm my Dell M1210, all my performance problems virtually disappeared. This issue was such a pain in the ass that I have made it a personal mission to seek out every DELL XPS1210 customer and tell him to ditch Media Direct. I am in sales and travel quite a bit. So in the past 3 weeks, I have interacted with 7 M1210 users. For instance, in Airports it is easy to spot the other Business travelers and it is customary to size-up each other’s package (PC that it). “Hi there, I see you have a M1210. Are you having a performance problem with your Outlook?” At first, I often get this “who the heck are you” look but after I explain more, I see tears form in their eyes. Tears of gratitude! Last Sunday in salt Lake airport, I help a guy named Dave delete Media Direct from his Dell. I was rewarded with free beer until I could drink no more (I had to catch my flight.) I even receive an unsolicited hug from a lovely lady in Irvine. It was Kind of like the YES YES YES response in kujo #35 entry.

    So a word to the world; do you want free beer or hugs? Spread the love. Tell all the distraught Dell customers about this fix and you will be rewarded beyond your delights. One more thing. This problem in not limited to VISTA. I have seen XP users with the same problem. It is not as bad, but still painful.

    Like Tim said, It is always nice to see MS engineers visiting us (the little people). I will try the patch Ellen # 39’s recommended but how can we get the real root of this problem; Dell’s MEDIA DIRECT. After I fixed my PC, My IT guy (Charlie) called Dell support and they said, “Oh yea, we are aware of this issue.” THEN WHY THE #@&K did you not tell us in the last 6 support emails we entered? “I am sorry sir, I will report this to my manager” BULL. This is undoubtedly a Dell problem!

    Once again. DIRK #10; YOU ARE A GOD! I thank you. Kujo #35 thanks you (granted a bit better), I know my buddy Dave in Salt Lake thanks you. Heck even today Will (you know who I am talking about) will thank you. I just told will over the phone. “I have been searching the web for weeks” said Will.

    Will, I prefer Gordon Biersch Pilsner.

    Thad (San Jose)

  18. The whole purpose of my buying Outlook was for the purpose of e-mails. How could Microsoft get it so wrong!!

  19. BTHX and a cookie goes to Bazza says:

    March 17th, 2007 at 11:48 pm

    My Outlook 2007 is alive and kicking after your advice 🙂

    You are the best man 🙂

  20. Hi folks. this was an Email from Will.
    see thread #42
    ———————————————-
    Hi Thad
    I tried two things…. First I went into Outlook to the Actions -> Trust Center -> Add-ins -> COM Add-ins and manually turned off the entry for “Outlook Addin” (other web references said it was equivalent to removing the MediaDirect without actually deleting it from the system). This immediately fixed the recurring appointment entry problem in the calendar. It also seemed to relax some of the disk crunch activity (less, but still some left). Then I tried completely deleting the MediaDirect and it made no change compared to disabling the Outlook addin. I was hoping deleting MediaDirect would show further performance improvement, but I actually could’ve gotten away with just removing the addin. No big deal, I wasn’t using the MediaDirect anyway.

    From what I read on the web the MediaDirect showed vast improvement in Outlook performance for many users (eliminating the disk crunch considerably). In my case it help just a little on the performance because I had already implemented so many other recommended workarounds on my Vista OS like disabling the pre-fetch feature and reducing many of the system startup memory hogs.
    -will

    I still want my beer!
    -thad

    But bottom line is the Outlook appointment recurrence problem is a problem no more…. Thanks.

  21. Someone please help me!!

    I’m running Outlook 2007 on a Thinkpad T43 with an XP OS. Outlook 2003 was running super (1Gb pst file until I installed Outlook 2007.

    I have installed the latest patch from MS. Disabled all the add ins… it is still very slow and freezes my laptop.

    Any suggestions. Thank you in advance.

  22. I tried Bazza’s (#27) suggestion(vista) and also did MS’s http://support.microsoft.com/?kbid=933493(xp & vista) & for the most part things are well. I have no probs on my XPsp2 laptop, but on my Vista desktop (1 gig ram, 2.0 rating) whenever I type someone’s name in To/CC/BCC my Outlook completely freezes from about 15-45 secs each name I try to type. If I have to backspace it takes another 30 or more seconds. I’ve seen this same thing on other vista machines in my exchange-connected office.

    Any ideas?

  23. This sucks…I tried calling microsoft and they could not figure it out, Sat on the phone for hours being their puppet!! Still no solution good thing I did not pay for any of it. It seems to be hit or miss…I have two Identical sony Laptops and one it works on and the other it does not.

  24. Thought I had the obviouse workaround, run office 2007 without outlook but stick to the old outlook 2003 (running BCM) … ok, few problem swith looking for word 2003 as the email editor, but you can run that alongside word 2007.. but now every time you use word 2007 after runnign word 2003 it does the “installing /configuring office 2007” and asks you to restart.

    whatever happened to http://www.hitbillgates.com?

  25. I’ve tried splitting up my .pst into multiples, and although the mail does indeed seem to move into the new .psts, the file size of the original Outlook.pst doesn’t decrease any. Performance has made a very, very slight improvement, but not really worthy of note. I’ve tried closing Outlook numerous times, in case it somehow doesn’t actually delete the e-mails from the original .pst until the app quits, but no luck.

    Can anyone help me out here? I’m running on a dual-core 2.80 GHz processor and 2.50 GB of RAM. There’s no way it should be this slow. >_

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