Calc multi-threading does NOT work

English
#1

Firstly my linux Mint is absolutely kept upto date.

Calc is not mulit-threading my spreadsheets correctly. My spreadsheets are large and generally full of cell formulae. Saving and calculation is chronically slow. generally about 10 minutes but 20 minutes in some situations.

To back up my statement I have run System Monitor at the same time as Saving or Calculating runs on the spreadsheet. This shows only one CPU out of twelve is working at 90 to 100% while other CPU’s are operating at approx. 0.5 to say 8% with the majority of them at 0%. Memory usage is just hovering about the 3%.

Now while this going on, if one loads a Time Stamp backup you will suddenly see the majority of the CPUs suddenly light up and start running at 95 to 100%. In my case this was 8 CPUs, including the one Calc was using. Memory usage increased to 13%.

Time Stamp is a program that is written to use multi-threading and operates at a comparative incredible speed whereas Calc is but a slug. (my computer is 2 terabytes, memory 32gig, intel 6 core chip).

Can LibreOffice Calc not be coded to use multi-thread properly or are we forever stuck. As a coding complete layman I have no idea what the issues are - but if Timestamp can operate fast why can’t Calc ??

1 Like
#2

As a start, a data copied from your Help → About would already help seeing if Calc’s threading support is enabled. It is not perfect, but still helps in some cases. However, it depends on your data being columnar in structure, and have identical formulas per column, to allow vectorizing. Which is another unknown variable in the equation.

#3

Hi Mike - thanks for your response, Calc is showing threading support is enabled. and yes to identical formulae per column. So what you are saying is that backing up in Time Stamp, which is just copying, is a different call on resources than cell formulae in a spreadsheet which can/ involves multiple dependencies per piece of information/cell? Surely the Calc program can be programmed to use a number of CPUs at once to their full extent though and not just one CPU?

#4

I am saying nothing about “Time Stamp”, not a single word, thanks for not putting your words into my mouth in the future :wink:

And without bug reports with specific document examples, showing bad performance, there’s nothing that can be done. We do have threading support; but as said, it’s not perfect.

#5

Sorry-not trying anything on, “putting words” etc., don’t understand what you meant exactly by “vectorizing”, as a user and layman. Bug reports I would not send because I don’t understand how secure my information in my spreadsheets is if I did this. Indeed I don’t know how to instigate and send bug reports. I’m merely reporting what I see happening, hence the query.

#6

It is publicly available.

Shrug; there’s nothing to be done, then…

#7

Background

Trying to translate into layman’s terms

Yes, @mikekaganski, something will be “lost in translation”. I do not intend to imply anything on your behalf, merely posting my interpretation of the issue at hand and suggestions for a viable way forth, anchored - as it were - in your concluding statement/shrug :wink:

Reality check

A sample file - either submitted in this service for review or in the bug tracker to illustrate a situation which may constitute a bug - will be publicly available.

Mandatory condition

For properly addressing the issue as presented, a sample file is required. The sample needs to have source content structured the same way and in the same amounts as the problem file, and formulas need to be identical to what you have. A copy of the “help - about” information, fetched by the copy button in the middle of the info “splash”, should also follow.

An aside

There are different ways to mangle content (bulk replace, randomly generated content, “lorem ipsum”, etc.). Diferent methods will be relevant for different settings. Cf. the mention of “faithful representation” below.

Faithfully mimick real data and formulas

If you consider also your formulas as sensitive matter (intellectual property, or holding confidential info), this adds to the challenge of faithful representation.

  • If you alter formulas also, make sure that the resulting file displays the same issue as the original before submitting.
  • If you have custom functions/macros running, They must be embedded in the sample file.

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