Excel 2008 EXTREMELY slow

Discussion in 'Mac Apps and Mac App Store' started by ak004m, May 20, 2008.

  1. ak004m macrumors newbie

    Jun 17, 2005
    I'm trying to use Excel 2008 (I wish I still had my old 2004 CD with me) to do some plotting and it's near impossible. I'm plotting spectrum data off of an optical spectrum analyzer, so we're talking some 3000 data points. I select the data, create a chart (annoying as hell in itself) and once the chart shows up I can't do anything without at least a 10-20second wait, I can't select an axis, move the chart, rename it or anything. Why is this so slow and is there anything I can do to speed things up??

    Oh, and doing such plotting using an old school Excel on an old computer running Windows 2000 was no problem at all.
  2. NAG macrumors 68030


    Aug 6, 2003
    Yup, using excel for anything with a lot of data is painfully slow. Office 2008 is the new Word 6. Office 2004 is faster even on intel macs (I'm not joking).
  3. seanyashi macrumors newbie

    Jan 15, 2009
  4. Consultant macrumors G5


    Jun 27, 2007
  5. TShanks19 macrumors newbie

    Jun 14, 2010
    my fix

    deleting the ~Users/Library/Preferences/com.microsoft.office.plist fixed my problem. I was only having problems when I was connected to a specific remote disk (which I almost always was). It took 20 seconds to close a LOCAL file that I had just opened (and this was a simple .txt file). If I wasn't connected to that remote disk, I could close that just-opened local file instantly. Deleting the office plist file fixed it completely. (The plist file is, of course, recreated by the system immediately.)
  6. mfripp macrumors newbie

    Jun 30, 2010
    A solution to slow charts in Excel 2008!

    I hoped that this problem was just a case of some little bug in Excel 2008 that could be fixed and make charts just as fast as in 2004. But actually it looks like a more fundamental problem with how Excel 2008 charts get drawn on-screen on the Mac.

    That's the bad news. The good news is, there are a few effective workarounds:

    1. Avoid using markers in charts with long data series. Alternatively, use a square marker instead of other shapes.
    2. For line charts, set the line width narrower. At 1 point or less, Excel 2008 (12.2.5) can draw a 10,000-point series in about 1 second. At 2.25 points (the default), it takes 5-15 seconds to draw each series (which happens every time you touch the graph or scroll it into view).
    3. If you use thick lines (which you shouldn't for this much data!), set the "cap type" to flat instead of round (the default). With flat caps, it takes 5 seconds to draw a 10,000-point series with a 2.25 pt; with square caps it takes 10 seconds, and with round caps it takes 15 seconds.
    So, to summarize, with the default settings, Excel 2008 (or actually OS X) spends lots of time (about 15 seconds per 10,000-point series) drawing line segments with round caps for each point in the series. It does this for every series, every time you touch the chart, which can easily add up to a minute or more for charts with several long series. If you make the line thinner, you can reduce this time to less than a second.

    It looks like this may actually be Apple's fault. Excel 2008 seems to send standard instructions to OS X to draw line segments with rounded caps, and then OS X takes a long time to draw all of them.

    You can verify this by "printing" the chart to a PDF and then opening it in Preview. Preview (at least on OS X 10.5.8) takes just as long to display each series from the PDF as Excel took to draw it on screen. On the other hand, if you open the PDF in Adobe Illustrator or Acrobat, the chart is displayed instantaneously.

    As another verification -- if you convert the line segments from 2.25 pt to 1 pt in Illustrator and then save the PDF, then Preview displays it in 1 second (instead of 15). But if you then zoom in in Preview, it takes longer to draw.

    The PDF itself seems to be pretty clean. If you open it in Adobe Illustrator, you'll find there are just simple line segments for each data point. So kudos to Microsoft for using standard, simple PDF commands for on-screen display and export, but Apple had better find a way to display them more quickly!

    By the way, has anyone tried working with big charts with thick lines on OS X 10.6? Is it any faster?

    (Thanks to http://forums.appleinsider.com/showpost.php?p=1417910&postcount=28 for the hint that got me started on this!)
  7. mfripp macrumors newbie

    Jun 30, 2010
    Maybe it's Microsoft's fault after all

    After poking around a little more, I'm inclined to think the slow charts might be Microsoft's fault after all. Excel draws each series in a chart with one disconnected line segment for each data point. If you have thousands of data points, this makes thousands of disconnected line segments. OS X is slow to draw disconnected line segments, especially with round end caps (see page 161 of "Quartz 2D graphics for Mac OS X developers" by R. Scott Thompson and http://developer.apple.com/mac/library/samplecode/QuartzLines/ ), so it tends to choke when it gets thousands of them from Excel.

    The right way to draw these series would be to use connected line segments. OS X seems to be able to draw those hundreds of times faster. So someone at Microsoft should change their chart drawing code to do that. (And Apple should improve Quartz to draw disconnected segments as quickly as connected ones.)

    In the mean time, this points to a couple more workarounds:
    1. Use area charts instead of line charts. Excel draws area charts with connected lines, so they are very fast. This is more useful for illustrating the source of the problem than solving it.
    2. More useful: Turn on the "smoothed line" option for your line charts. This makes the lines more complicated, but Excel will draw them with connected segments, which are much faster.
  8. jgauthier96 macrumors newbie

    Nov 8, 2010
    Solutions that work!

    Not to my credit, but i found this in another forum and you will LOVE it!

    the 2 solutions that seem to accelerate my Excel 12.2.7 on Mac OS 10.6.4 which crashed regularly when I tried any large action on a large sheet were:
    1) removing recent files
    2) Font App: resolving duplicates: Mac and Office both have their own version of Arial, which made Excel spin to a stall and/or crash.


    "Try running the OS X app Font Book & using the Validate Fonts & Resolve Duplicates routines. Shut
    down for a minute or two & see if things improve after restarting.

    It may also help to go to View> Customize Toolbars & Menus & clear the check
    for "Show typefaces in font menus".

    Also, if you are not already doing so, do most of your work in Normal view.
    Page Layout View consumes a lot of overhead & interaction with the printer
    subsystem. Use it sparingly.

    Additionally, in Excel Preferences:

    Make sure Save AutoRecover Data is set for no more frequently than every 10

    Turn off Provide Feedback with sound,

    Limit the number of recently used files (or turn off altogether),

    Turn off Provide Feedback with Animation as well as the Paste & Insert
    Options Smart Buttons.

    HTH |:>)
    Bob Jones
    [MVP] Office:Mac"

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