$ rio mbtiles --help
Usage: rio mbtiles [OPTIONS] INPUT [OUTPUT]

  Export a dataset to MBTiles (version 1.1) in a SQLite file.

  The input dataset may have any coordinate reference system. It must have
  at least three bands, which will be become the red, blue, and green bands
  of the output image tiles.

  If no zoom levels are specified, the defaults are the zoom levels nearest
  to the one at which one tile may contain the entire source dataset.

  If a title or description for the output file are not provided, they will
  be taken from the input dataset's filename.

Options:
  -o, --output PATH       Path to output file (optional alternative to a
                          positional arg for some commands).
  --title TEXT            MBTiles dataset title.
  --description TEXT      MBTiles dataset description.
  --overlay               Export as an overlay (the default).
  --baselayer             Export as a base layer.
  --format [JPEG|PNG]     Tile image format.
  --zoom-levels MIN..MAX  A min..max range of export zoom levels. The default
                          zoom level is the one at which the dataset is
                          contained within a single tile.
  --image-dump PATH       A directory into which image tiles will be
                          optionally dumped.
  -j INTEGER              Number of worker processes (default: 1).
  --help                  Show this message and exit.

$ time GDAL_CACHEMAX=256 rio mbtiles NE1_HR_LC.tif \
> -o ne.mbtiles --zoom-levels 1..5 -j 4

real    0m44.925s
user    1m20.152s
sys     0m22.428s