Very slow viewing Raw thumbnails

[Brit.b]

When I try to open Raw files (or phototomerge files) in the latest version of Photoshop , Explorer says, "working on it" for about 20-40 seconds before the thumbnails appear. (I just installed the latest version of Camera Raw) However, the thumbnails appear instantly when looking at Windows Explorer on its own (not through Photoshop). Any ideas why? Other image files appear almost instantly. It is really slowing down the work process 

[Kevin Stohlmeyer]

@Brit.b Have you tried resetting your preferences?

https://helpx.adobe.com/photoshop/using/preferences.html#reset-preferences

[Brit.b]

Thanks, but it didn't work. Perhaps having 110 Raw images in the folder slowed things down when opening in Photoshop, but the thumbnails open instantly in the same folder in Windows Explorer. 

[D Fosse]

Just to be clear, because I'm getting a little confused when you talk about "thumbnails":

Your screenshot shows the Photoshop > File > Open menu? Whereas opening by double-clicking in Windows Explorer works fine?

[Brit.b]

"Your screenshot shows the Photoshop > File > Open menu? Whereas opening by double-clicking in Windows Explorer works fine?" 

Yes that is correct

[Trevor.Dennis]

Are you seeing the thumbnails via Lightroom or Bridge?

I use Bridge, and it needs to build a library which takes several seconds, but after that things should work smoothly and without delay.

[Brit.b]

Yes, it works quickly in Bridge once the thumbnails are created. But it is still slow when opening in Photohsop 

[Rob_Cullen]

"thumbnails appear instantly when looking at Windows Explorer"

In Windows Explorer you are looking at an embedded JPG preview image that is contained within the RAW image file.

You are not looking at the RAW image data rendered!   Might explain any 'speed' difference.

And how much system ram do you have to cache 110 raw files for ACR?

[Brit.b]

I have 64 GB RAM with a Ryzen 9 5950x processor. It seems to me that it used to open much faster with as many RAW images. I did reset as well.