Nikon Z-7 Raw files are processed improperly with PhotoShop CC

Nikon Z-7 RAW files do not process correctly in PhotoShopCC newest version. Older Nikon RAW files - 35 MB in size, gave a jpeg output of similar size to send for large sized printing.

JPEG is a lossy compression file format that reduces file size typically by 1/2 to 1/7 the original raw file size. If the JPEG output from a previous 'Save As' in PS was equal in size to the original raw file (35MB) this is not normal. This could happen if the raw file was shot at very high ISO setting and/or long exposure with very high uncorrected Luminance Noise. The resulting noise in the image will cause the JPEG compression algorithm to become less efficient resulting in larger than normal file size. See this post for more typical results:

http://regex.info/blog/lightroom-goodies/jpeg-quality

The new Z-7 NEF [RAW] files - 54 MB in size, processed exactly the same in PhotoShop CC, give a jpeg output of 21.5 - 22.5 MB.

This is a typical file size when using  raw files that have low-noise (i.e. low ISO setting) when using the maximum 100 Quality setting. At the above post the author found using higher than the LR default 75 Quality setting provided provided no "visible" improvement in the JPEG image.