The current version of a sentence I'm writing has the structure:

Computing [such and such] is the most computationally expensive part of [algorithm].

At the moment, I cannot think of a better phrase to replace "computationally expensive". I know it is legitimate to say this ("computationally expensive" has been published numerous times). However, it sounds a little informal to me.

What are some alternatives to "computationally expensive" in the above sentence?

  • 4
    Why does this sound informal to you? It's technical jargon (as e.James says) and it not a term commonly heard on the street, for instance.
    – kajaco
    Sep 14, 2010 at 14:42
  • Perhaps it's because "expensive" pertains to "spending" and how do you spend computation? You can spend money, spend time, etc. Sep 17, 2010 at 5:54
  • 5
    It is spending time (cycles) and/or money (memory, albeit a stretch).
    – kajaco
    Sep 17, 2010 at 15:48
  • @DouglasS.Stones "expensive" → "intensive"?
    – endolith
    Aug 6, 2016 at 3:13

5 Answers 5


The correct answer will depend on your audience. For a highly technical audience such as engineers and programmers, you could keep the original sentence or use one of the more precise terms suggested by Midhat. Everyone in that audience will immediately understand your message because they are already familiar with the underlying concepts. To them, the important information is the how and the why, and your sentence delivers.

For a less technical audience that is still somewhat familiar with the technology, I would choose a term that has more specific meaning for the members of that audience:

  • We can improve [algorithm] by making [such and such] more efficient
  • [such and such] requires more (time/memory) than any other part of [algorithm]
  • [algorithm] does not meet our needs because it spends so much time on [such and such]

For a non-technical audience like high-level management, the technical details should be an afterthought. If you are worried that the term "computationally expensive" is overkill for your audience, you should probably remove the other technical details as well. This does not imply that your audience is too stupid to understand what you are saying, just that they are more interested in other things:

  • We can improve [business application] by spending more money on [resource] (for [algorithm])
  • Thanks, dot-point 2 is what I'm after. Dot-point 1 is what the reader is meant to infer from the sentence. [Oh, and it's a mixed-specialty academic audience.] Sep 14, 2010 at 7:14
  • Ah, mixed audiences. Tricky! :)
    – e.James
    Sep 14, 2010 at 7:19

resource intensive, CPU intensive, Memory intensive

  • 1
    I tend to use the word 'workload' since there were many occasions where non-technical person could not immediately realize, physically, what "resources" refers to.
    – Gapton
    Feb 28, 2012 at 2:09
  • Puts a heavy workload on the CPU.

The wording is less technical so your general audience will understand, and to a technical audience they will understand it just as well, with not much room for misunderstanding.


I guess you could say it takes up a lot of CPU time, memory, or both. Which is also more precise.


You can say "A is computationally more costly than B."

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