Why is build time longer when I remove all image processing?

This is a bit puzzling to me, but when I remove Hugo’s image processing from my project and compare the build times with and without the processing I’m getting longer build times in the latter case.

Image processing (enabled)

First run:

hugo --gc --minify
Start building sites … 
hugo v0.95.0-9F2E76AF linux/arm64 BuildDate=2022-03-16T14:20:19Z VendorInfo=gohugoio

                   |  EN    
-------------------+--------
  Pages            |  9030  
  Paginator pages  |     0  
  Non-page files   |  1787  
  Static files     |    29  
  Processed images | 16551  
  Aliases          |     0  
  Sitemaps         |     1  
  Cleaned          |     0  

Total in 185897 ms

Second run:

 hugo --gc --minify
Start building sites … 
hugo v0.95.0-9F2E76AF linux/arm64 BuildDate=2022-03-16T14:20:19Z VendorInfo=gohugoio

                   |  EN    
-------------------+--------
  Pages            |  9030  
  Paginator pages  |     0  
  Non-page files   |  1787  
  Static files     |    29  
  Processed images | 14505  
  Aliases          |     0  
  Sitemaps         |     1  
  Cleaned          |     0  

Total in 144611 ms

Image processing (disabled)

First run:

hugo --gc --minify
Start building sites … 
hugo v0.95.0-9F2E76AF linux/arm64 BuildDate=2022-03-16T14:20:19Z VendorInfo=gohugoio

                   |  EN   
-------------------+-------
  Pages            | 9088  
  Paginator pages  |    0  
  Non-page files   | 1807  
  Static files     |   29  
  Processed images |    0  
  Aliases          |    0  
  Sitemaps         |    1  
  Cleaned          |    0  

Total in 190807 ms

Second run:

Start building sites … 
hugo v0.95.0-9F2E76AF linux/arm64 BuildDate=2022-03-16T14:20:19Z VendorInfo=gohugoio

                   |  EN   
-------------------+-------
  Pages            | 9088  
  Paginator pages  |    0  
  Non-page files   | 1807  
  Static files     |   29  
  Processed images |    0  
  Aliases          |    0  
  Sitemaps         |    1  
  Cleaned          |    0  

Total in 181412 ms

I know there’s a ~50 page difference between when I ran the builds, but surely they can’t be responsible for the build without image processing being ~36 seconds slower than with image processing :thinking:

Hi @figment-rust

so a few reasons i see straight away when you have images disabled are:

  1. There are 50 extra pages.
  2. There are 20 additional non-page files.

one might be able to share more if you share more of the project thanks


those additional 50 pages might be the reason due to some complexity that you have added