Since this touches raw handling you need to look at this a bit more seriously.
Camera cache involves PS CC performance. I set the cache to 4GB (loss of speed when used). I set the location t my temp drive, a SDD (gain speed back). If anything, leave the size alone and use the fastest drive as your raw cache.
I set ACR to use my camera serial number as well as ISO settings. That is just me. You can dispense with that and see very little difference unless you process a large amount of images. I use only two cameras and usually at 400 ISO so it works for me.
JPEG and TIFF handling, I want ACR in between even if I often use 'open' w/o making any change. This is a convenience for me, nothing else.
Default
My preferences