Admin Forum:Purging an image and regenerating delay

I know that after uploading a new version of an image, we generally access the purging page to force the software to make a new thumbnail of it. But I don't know why, that the time for refreshing became too long these days: sometimes it even takes hours! It's a pain for me that I cannot visualize the layout with the correct image and have to spend a long time to continue editing. Am I the only one to feel it inconvenient?