about database size--primary group

One database has 3 primary groups: group1.mdf, group2.mdf and group3.mdf

Group1 and group2 's initize size is 100 MB and autogrowth is none(not enabled).

Group 3's initize size is 100mb and autogrowth is By 15 MB , unrestricted growth(enabled)

Will this setup has problem when database keeps growing? DOn't want to have "run out of space" issue. Have enough big hard drive for these .mdf files.

Thanks