Performance improvement: Swatches cause a huge slowdown on catalog pages.

[apiuser]

Feature request from paales, posted on GitHub Oct 14, 2016

Preconditions

1. 2.1.2

Steps to reproduce

1. Create a category/search page with a lot of configurable products with (image?) swatches
2. Make sure the normal cache is loaded (loading another page)
3. Load the category page.

Expected result

1. Page should load timely

Actual result

1. It seems underlying product's images are loaded as well. These images aren't used when rendering a category page.

They are loaded here: https://github.com/magento/magento2/blob/fb6faf5975fd7580eb407f089f8fbcacd5ee42f5/app/code/Magento/C...

I'm seeing a huge performance boost when I'm disable that line, and it doesn't seem to degrade in functionality (it doesn't use those images).