Optimising Min/Max temporal raster search in python/gdal

I need to search across ~100 1200×1200 raster tiles and produce a min and a max raster. Along the way i also want to exclude values that are over 1 or less than 0. What would be the quickest method to do this in python with gdal? I was previously loading all the rasters into memory and then looping over the pixels, but this seems the slowest possible method.

Thanks!