Oh, I was meaning to file something like this.

I *think* this is because MMV preloads the previous and next image at the same time as loading the current one. I haven't had time to verify this by looking at the code yet, though.

Whoa that was slow.

Bartosz: the prev/next image should only start loading when the current one has finished, although the way that is implemented is not perfect (e.g. the API request for the image metadata might start sooner).

This could also be caused by thumbnail rendering times, since the original image is huge.

Change 127439 had a related patch set uploaded by Gergő Tisza:
Disable preloading of fullscreen-sized image

https://gerrit.wikimedia.org/r/127439

Change 127439 merged by jenkins-bot:
Disable preloading of fullscreen-sized image

https://gerrit.wikimedia.org/r/127439

Change 127801 had a related patch set uploaded by Gergő Tisza:
Disable preloading of fullscreen-sized image

https://gerrit.wikimedia.org/r/127801

Change 127802 had a related patch set uploaded by Gergő Tisza:
Disable preloading of fullscreen-sized image

https://gerrit.wikimedia.org/r/127802

Change 127801 merged by Catrope:
Disable preloading of fullscreen-sized image

https://gerrit.wikimedia.org/r/127801

Change 127802 merged by Catrope:
Disable preloading of fullscreen-sized image

https://gerrit.wikimedia.org/r/127802

Probably fixed, then.

(It's not been annoyingly slow for me anymore for the last few weeks.)