Yes, when opening a folder of 7000 raws, there are no images at all until ~20 minutes or so.
What sort method are you using? Filename sorting is the fastest. The other methods are slower to very slow.
In the Save As process, I am using Embedded JPEG previews.
I expect you to be able to save 1-2 images per second depending on your settings. Scaling takes time, sharpening takes time, limiting the file size takes time, watermarking..., etc. If you were only wanting full size images you can instead extract the JPEG previews out of the RAW files (you'll have no further options for changing the resulting image) and that is quite fast.
If the disk is slow then everything slows down.
If you operate on images that are stored on your computer's internal hard drive, do you still experience the same level of slowness?
-Kirk