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