Dear Neil,
please check the codecs you have. Actually Windows RAW codecs (https://www.microsoft.com/en-us/downloa … x?id=26829) are quite OK w.r.t. speed. You’ve probably installed some Nikon codecs which do some image sort of image post processing enhancing/filtering/corrections/etc. This Is done in codec and CR does not have control over that.
This will influence all operations where we read images - features detection, depth map calculation, texturing, coloring,…
Please consider updating your codecs pack.