model database: New default data and log file size is 8MB and default auto-growth is 64MB. This ensures that any new database created without explicitly specifying the SIZE/FILEGROWTH parameter will have 8MB initial size for all data and log files and 64MB for auto-growth for both data and log files.
For data files, having a 64MB autogrow, aligns with 1 PFS interval (which covers a range of 8088 pages = 64MB). For log files, having a 64MB autogrow helps with sizing the initial VLFs correctly so that they can be garbage claimed (wrapped-around) without which the log can keep growing.
This is much better than the prior default of 1 MB size and 10% auto-growth. Percentage growth leads to eventual pain.