Super Mario Galaxy is approx. 4.37 GB (4,589,424 KB (4,699,979,776 bytes)) in size and has two partitions on the disc. Partition 0 is empty, while as Partition 1 holds about 3,375MB of data. Specifically, it holds up to 2,371 files. According to the Disc Data Size, this is 3,539,038,208 bytes large.
Super Mario Galaxy 2 is also 4.37 GB (4,589,424 KB (4,699,979,776 bytes)) in size, but it has three partitions on the disc. Partition 0 is empty, Partition 1 holds basic system files (partition.bin [tmd.bin, cert.bin, h3.bin], boot.bin, bi2.bin, apploader.img, main.dol, fst.bin, _sys directory [Wii system WADs] and __update.inf) and Partition 2 holds all the data. The Disc Data Size shows the entirety of the disc data as 1,680,934,912 bytes in size, which is about 1,603 MB. 3,985 files are present on the disc.