Time Machine: What Size External HDD for backups?

Since HDDs do not change price linearly with capacity... it makes sense to pay a tiny bit more for additional capacity. With 2TB drives well under $100 now... you may find that you you save almost nothing (may $10 or so) to get much less capacity.

BTW: the rule of thumb is 2X the size of the drive you are backing up. I would assume that you will eventually fill the 1TB... so I would go with 2TB.

/Jim

 

For changing the interval of backups, please look at this tool: https://www.macupdate.com/app/mac/26704/timemachineeditor

 

As was suggested 2 times the size of the drive you're backing up is a good rule of thumb. Although with the low price difference between 2 and 3TB external drives you might want to consider a 3TB.

As for frequency of backup, having had drives fail, I would recommend no more than a 2 or 3 hour window between backups and truthfully there is usually no reason not to leave it at the default.

 

I have the same mini with a fusion wiht about the same data (330GB).

I have a 2TB. After about 3 months it is only about 1/3 full.

If you do not have a virtual machine (parallels) you will use far less TM drive.

 

I agree with flynz4, twice the size of the drive is the best start. But the larger the TM drive, the more backups you can store before TimeMachine starts overwriting the old stuff. If you create/edit a LOT of files, then the larger drive will be well worth the money if you consider TimeMachine to be your only backup (which is a bad idea, by the way).