You MUST change the defaults for TempDB or you'll end up having 73 fragments by the time it grows to 1GB.
I normally start out a new system with 1000MB allocated to the mdf and 200MB-250MB allocated to the ldf. I setup the growth on the mdf to 250MB and 100MB on the LDF. Then, I watch it for a month. After at least one "month-end crunch" has passed, I'll set the sizes to whatever the current sizes are + 20% and bounce the service so I have a nice contiguous TemDB where the growth isn't going to take anyone by surprise.
--Jeff Moden
Change is inevitable... Change for the better is not.