Is there an option like "--demuxer-min-bytes" to determine when mpv will buffer again

[hululud]

I want to reduce the time of reading file from my hard drive to avoid damages, so I use the following options:
cache=yes demuxer-max-back-bytes=64M demuxer-max-bytes=2048M
It is helpful when playing small size video.
but for the video that is larger than the memory size, the player will cache and keep the size of 2GB.
This makes mpv behaves like the "cache" option is not used after the cache size is full! (still continuously reading from the drive while playing)

Is there an option to use the cache first, and buffer again when the cache run out (like when the cache is only 200mb left)