[Ryan Provost]

The numbers of DNxHD refer to the bit rate of the file. So more frames in the picture equates to a higher data rate. These are some of the possibilities:

23.98 the possible DNxHD codecs are: 36, 115, 175, 175X.
25 the possible DNxHD codecs are: 120, 185, 185X.
29.97 the possible DNxHD codecs are: 145, 220, 220X.
(This Wikipedia link is really a good reference: https://en.wikipedia.org/wiki/List_of_DNxHD_codec_resolutions)

If your source material was only 8 bit you really aren’t gaining much by making it be 10 bit later on. As a best practice I always try to match the bit rate of my source material to the a DNxHD or ProRes bit rate.