Image preview thumbnails fail to load

Question

I open a folder full of tifs, they all render their thumbnails immediately, I open the folder within that and some render but the rest freeze.
Why is this?
On my old Windows machine the same folder all renders instantly, that machine is 4 cores and 8gb ram slower!
It's making life incredibly tedious, as when i click a thumbnail it takes a while then shows a preview after I press space, then it keeps this thumbnail. Tedious if you go through hundreds.

Answer 1

Hi E,
I am not sure if QuickLook makes an index or store this with Finder's one. But generally the first attempt takes a longer time than next visits to this folders. I also have a folder with some 1000 images with 5 to 20MB each and icons previews are slower sometimes.
As an acceleration option Select All files and press Space bar, you will get an icon that enables you to preview multiple files with a scroll bar, this will make first previews faster.
Good luck.