LR does not display generated 1:1 previews in develop straight away ?

…have created 1:1 peviews beforehand.

Now when I scroll through them in the develop module, the files open but change appearance after about 4 seconds. They don't do this in library, but only in develop. Very annoying.

By @zobeleye

The modules work differently.

In the Develop module, the priority is maximum image quality so that you can see properly to make the best editing decisions. So in Develop, what you see is a full bit depth wide color gamut render, from the raw data through all applied Develop options. In other words, it is not using anything pre-generated in the preview cache. The Develop module does use a cache, but it’s the full quality Camera Raw cache. This is why you have separate controls in Lightroom Classic for the preview cache and the Camera Raw cache. In Develop, display time is about whether the current state of the image matches what’s in the Camera Raw cache for it, and if it isn’t up to date or isn’t cached, it must be rendered. 

If it must be rendered, now the Develop display time depends on the speed of the CPU and GPU, and also…the more edits have been applied (masks, healing spots, removal tool spots…) the longer it will take to render a particular image. Higher pixel dimensions will also slow Develop rendering, such as a raw image from a 50 or 100 megapixel camera. It can also depend on the speed of the volume where the Camera Raw cache is located, but recent Macs have such fast internal storage that if the Camera Raw cache is left at its default location (the internal Mac startup volume), that storage should be some of the fastest available. 

That’s the Develop module. Anywhere else, image display time is different because previews are used instead.

In all other modules and views, such as the Library module Loupe and Grid views, or the Book, Web, Print etc. modules, what you see is an 8 bits/channel Adobe RGB JPEG preview of whatever size is needed. If you are looking at the grid, you see previews generated at thumbnail size. If you’re looking in Loupe, it could be a standard, embedded, or 1:1 preview depending on what’s been generated. These should normally display faster than Develop because all they should have to do is pull the JPEG preview out of the preview cache and throw it on the screen. If a preview is not already in the cache for an image, then it has to be rendered, and right now preview rendering depends completely on CPU speed, and (for bulk preview generation) the number of CPU cores. As of Lightroom Classic 14.1.1, the GPU is not involved in preview generation.

Hopefully that explains it: Compared to all the other modules such as Library, which use previews, Develop uses higher image quality specs and different hardware resources for rendering.

Develop generates its own fresh previews, it doesn't use the ones you have created in the Library Module.

If you want faster speed to show the preview in develop, I beleive the only way to get there is to upgrade your CPU and/or GPU.

in the future, to find the best place to post your message, use the list here, https://community.adobe.com/

p.s. i don't think the adobe website, and forums in particular, are easy to navigate, so don't spend a lot of time searching that forum list. do your best and we'll move the post (like this one has already been moved) if it helps you get responses.

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