LibreOffice 25.8: slow performance

[Uka]

Since I updated to LibreOffice 25.8 (currently 25.8.3.2, tested also with 25.2.7.2), I have encountered constant sluggishness in performance with any larger files (for example 1 Mb odt file with some 250 pages, footnotes, cross references and tables; 12 Mb ods file with 25 000 rows × 133 columns).

Slow performance is already obvious with the aforementioned text file: even basic actions such as typing and scrolling are laggy.

Even more annoying it is with LO Calc: I did a test performing the same action on two copies of the same file with 25.8.3.2 and 24.2.7.2:
Action: sort in ascending order (with 1 sorting criterium), performed on the data set of 25 000 rows × 133 columns.
Results:
– with v. 24.2.7.2 the action took 1 min 46 sec – which is acceptable;
– with v. 25.8.3.2: 8 min 52 sec – that is over five times longer.

Are there some critical configurations that can improve the performance considerably, or is there reason to file in a bug report?

Edit: Operating on Ubuntu 24.04.2 LTS

[ajlittoz]

Regarding Writer documents, strict styling dramatically improves performance compare to direct formatting.

Also, look at your tables. If cells contains so much data as to extend over several pages, you face a cache problem: apparently Writer collects full row data before rendering (needed to compute page break locations). You may consider splitting such “monster” cells into smaller ones (several rows) if this makes sense.

[Uka]

Sure, I’m aware of this. However, I’m just wondering about the LO versions, as the difference in performance speed is so obvious between (e.g.) 25.8.3.2 and 24.2.7.2.

[mariosv]

Please test in safe mode, Menu/Help/Restart in Safe Mode

Please attach a sample file, reduce the size as much as possible without private information,
and paste the information in Menu/Help/About LibreOffice, there is a copy icon.

[Uka]

Version: 25.8.3.2 (X86_64) / LibreOffice Community
Build ID: 69c620f4d99e06f4c05a0e551b1b572b8c7ede69
CPU threads: 12; OS: Linux 6.14; UI render: default; VCL: gtk3
Locale: fi-FI (fi_FI.UTF-8); UI: en-GB
Calc: threaded

Sluggish_spreadsheet_file.ods (991.6 KB)
Sluggish_text_file.odt (711.5 KB)

Of course, operating with this (greatly reduced) ods file is much faster than with the original. However, I tested it again with the versions 25.8.3.2 and 24.2.7.2, performing the action “sort in ascending order”, and the results were similar:
25.8.3.2: 20 seconds
24.2.7.2: about 4 seconds, so again five times faster.

By the way, I got the text file to work at an agreeable speed by rearranging some large tables and putting forced breaks here and there.

[ajlittoz]

Looking only at your .odt file because I am much more familiar with Writer, I see that the uncompressed document weighs more than 8 MB, compared to 711 kB compressed size. This means there is a lot of redundancy.

Your style dictionary is overcrowded with “real” table styles (type table-cell). I don’t know where they come from since there is no UI for them (don’t confuse them with so-called table “styles” when using Table>Insert Table) – perhaps from the .ods document if this is the source of your tables?. And you also tweaked manually your tables and ended up with direct-format similar table styles in table occurrences.

You don’t use character styles. Consequently, you create zillions of anonymous single-use character styles. Your paragraphs are also plagued (to a lesser extent) by direct formatting with the same result.

To make things worse, you already have 4883 editing sessions on your document (this shows you work a lot on it). When working so hard, it is better (personal opinion, you are free to disagree) to disable the improved comparison feature in Tools>Options, LO Writer>Comparison: untick Store it when changing the document in Random number to improve accuracy of document comparison section. This feature adds internal direct formatting whenever you change anything, be it a single character. The main difficulty is to remove existing markup. If I am right, File>Save as should do the trick (after disabling).

I also note there are citations. Since you substitute nonsensical text, I could not determine which citation manager, if any, you used. These are usually third-party “portable” add-ons. “Portable” means they don’t try to integrate with a specific office suite and implement their own management, independent from the application. They are responsible for a lot of direct formatting. This is not important as long as you don’t overflow Writer with your own.

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IMHO, loading time reflects the time needed to parse the style dictionary which is really overwhelmed by direct formatting. Try to get rid of the comparison markup first. Then apply character styles instead of your direct formatting (you’ll replace zillions of one-shot cases by ~5-10 styles which is a huge improvement). Think also about direct formatting on your paragraphs. It is mainly present in footnotes.

[Uka]

Thanks, I was able to improve the situation, at least to some extent. I added character styles for a couple of features; doing it with all the cursive, bold and underlined texts would be a lot of work at this point – maybe I’ll make more extensive use of styles in the next project.

[bananathematrixngc1569coffeecaketoy]

Workaround for extreme laggy scrolling (makes Writer unusable) in Writer 25.8.2.2 x86_64 that worked for me:

1. Go to Tools > Options.
2. On the left, expand LibreOffice Writer and click on View.
3. Under View on the right, UNCHECK “Smooth scroll”.