The real reason for Windows 7 to automatically build a 100M hidden partition

Why does Windows 7 automatically build a 100M hidden partition? The situation described below may not be the only real reason, but it should be one. I don't know if someone else has sent it.

do, is to make Win7 can be installed on the hard disk partitions cluster larger than 4KB, because in NTFS format, boot files can only work in 4KB cluster partition, which is used to store 100M of Win7 boot files, This installs Win7's primary partition and can be set to other sizes of clusters, even FAT32 format (to be verified).

we all know, the better the larger the cluster disk performance, small debris, but will take up more space, now have a big hard drive, sacrifice some space for performance is worth.

we can, drive started with Windows built-in functions to first establish 100M partition system partition and then exit, U disk or CD-ROM into the PM to establish a primary partition, and then specify the cluster size yourself.