How much larger is the size of a HSI compared to a MSI when they have the same resolution?

The size of Multispectral or Hyperspectral image corresponds to the number of spectral bands present in the data cube. For instance, if a typical multispectral sensor with 10 bands has a data cube volume of 1 GB, then a hyperspectral data cube with 100 bands would be approximately 10 GB in size.