Nicolaas1976 wrote:
It were only a few pictures which he does not want to sharpen directly. Going through the book a few pages and back results in sharpening after a few seconds. Strange that it is so slow. Just a new workstation HP Zbook 32GB RAM nVidia quadro 3100M and SSD HD wth dreamcolor screen.
Assuming "he" means LR and not the author of the book. There are many things that can impact rendering of book pages:
1) What type of files - RAW, JPEGS, TIFF?
2) If RAW, how many megapixels?
3) Are the files master photos or virtual copies?
4) What other adjustments have been applied to the files?
5) What is the resolution of the screen?
6) Are you running Windows 8.1. 64-bit? (apparently Windows 8.1, like Windows 7, comes in two flavours 32-bit and 64-bit?