My iMac has a 1 TB fusion drive. Right now, I only have about 100 GB of stuff on it. I want to get an external hard drive to use Time Machine. Would a 1 TB external drive be OK? Someone told me that the external drive should be bigger than the iMac's hard drive. But like I said, I only have 100 GB of data on the iMac drive. Sure, it will grow. But I can't believe I'll ever have as much as 300 GB on the iMac hard drive.
Time Machine, by default, wants a drive 2 - 3 times the size of your internal drive. As it updates backups, it will take up more and more space; once it starts to run out of space, it will delete the oldest backup to make room for the latest. So, it's your decision how many older backups you want; 1 TB may be enough, but be read for TM to possibly nag you, LOL.
Just to give you an idea, one of my Macs has a 2TB drive, the drive it's being backed up to is a 3TB drive. I have about 384GBs on my Mac with approx 1.73TBs free. My 3TB back up drive has 227.17GBs of free space left. I can recover files back in time until 10/1/2016 or about 4 months ago. For some that's enough. For others, not so much.
FWIW, 1TB is adequate but not ideal. The size has more to do with how many backups you can have before the oldest is erased, not how much you have on your Mac. 1TB is much better than none.
A 1 TB hard disk drive will be more than adequate for your present usage. For that matter, even 500 GB will be more than adequate.
Lots of good info. Thanks to you all.
Welcome.
Is 1 TB external drive big enough?
