SSD for time machine

[Jonathan Cross]

I have an M1 iMac on order to replace a PC.  I will want a 4TB SSD for Time Machine to back up the contents of the iMac and a 2TB external SSD.  I seem to have a choice, either use a portable SSD, such as a Sandisk, or an internal SSD in an enclosure.  The latter seems to be cheaper, but I am not sure its speed will match that of a Sandisk.  The port speed of the iMac is fast.

I would appreciate any thoughts.

Best wishes,

Jonathan

[Alan Klein]

I use a Western Digital WD My Passport 4TB on my Windows system desktop.  It's a disk type but was only around $100 and works pretty much plug and play in the USB jack so I can ignore it and let it do it's backup without any major oversight.  I'm sure their SSDs must be good as well and fast but were too pricey for me.  Good luck.

[tcphoto1]

The size of the Time Machine drive is rather irrelevant, it will purge the oldest backups when it approaches capacity. An SSD will likely speed up the backup time and be less prone to fail compared to a conventional drive. I moved the HD from an old MBP to an enclosure and it's worked fine for Time Machine.

[bobfriedman]

so time machine is quite invasive so I prefer to use a separate drive from all my others for backups, the time machine will use as much space as the drive allows and it is impossible to delete the backup without formatting the drive, learned this the hard way (unless they have fixed it).. SSD's are my preferred. I use a thunderbolt dock (OWC drive dock) and keep two backups on separate SSD's just in case one fails.

[BobShaw]

There really is no benefit to using an SSD for Timemachine. You would be.much better off with two normal drives so that you can have a second backup disk and rotate them regularly.  I would regard twice the size as the minimum. Three time is better and 6 TB drives are readily available.

[Joe Towner]

The speed difference between a HDD & a SSD or even a NVMe drive for backup is only relative to how big those 1 hour increments are.  Chances are the difference will not be noticed by you.  It's an iMac, so mobility/durability isn't the most important.  I personally prefer the standard 3.5" or 2.5" drives as the adapters are very common. Doing an enclosed model that's much faster has its tradeoffs if you damage the port accidentally.

Having 2 drives and swapping between them is a great help when TimeMachine really wants you to start a fresh backup.