Time Machine on a MacBook Pro with a 4T SSD - Would this be problematic?

[MalagLagoon]

I'm in the market to replace my 2015 MacBook Pro - that I'll have owned for 10 years this November!

For a time I've known that using a larger external drive (like 2T or 4T) is best when using Time Machine to back up my 2015 MBP. My 2015 MBP has a 1T internal SSD.

I want to buy an M4 machine with 4T of SSD storage space - but I have concerns that using a 4T external drive for Time Machine backups would be problematic - if backing up a 4T internal SSD. I've had this issue in the past using a 1T external drive for backing up my 2015 MBP's 1T SSD.

I'd like to continue using smaller external drives for backups that do not require external power. For my 2015 MBP I've added velcro to the back of my laptop for convenient backups. (see photo)

I'm still using a mechanical external HD. I have no idea if using an SSD for a Time Machine backup is a good or bad idea.

I'd like to continue using a small external drive like the one shown in then photo - but I don't think I've seen an 8T version in a similarly small package.

Thoughts?

 

[Bigwaff]

With backups, it really doesn't matter how long it takes. I'd look for a 6TB-8TB external bus powered HDD, as these are much less expensive than SSD storage.

 

[chabig]

A 6TB bus powered hard drive costs about $150. 6TB is the largest 2.5 inch HD available. SSDs are available in larger sizes. An 8TB portable SSD costs about $440.

 

[Alpha Centauri]

I have a 2TB internal in my MBP and for backups am using SSD's in my chosen enclosures.

For cloning the speed is quite nice to have as the SSD's Im using can run on the hot side. For TM however speed isn't a factor, so any HD should do the job. My end game was really about reliability of the medium. I did look at NAS with HDs but couldn't plc them where noise wouldn't be an issue. I guess I also bought the 990Pro SSD's in case I will use them for something else where speed could be a factor.

So just for TM, even a dual bay (minimum) NAS with large HD's could be an option, rotated off-site also. I personally chose to go with DAS and SSD coupled with a strict routine.

 

[MalagLagoon]

I just noticed that some MacBook Pros come with an 8T internal SSD. Although that amount of space would be luxurious for sure - backing this up regularly might be cumbersome or impractical. For example, it may not be possible to find a USB powered external drive (with no separate power supply connection) in a small enclosure. This assumes the backup drive would need to be larger than 8T to work properly with Time Machine.

 

[kohlson]

Just to make sure I'm on the same page, you're not filling up you new MBP drive when you get it, right? I'm assuming nowhere close. But for me, I have a 2TB MBP M1 Max connected to a 2TB HDD TM. It's been backing up nicely for years. Because TM only backs up data, this first time, and data that as changed after that. There are certain apps, like FCP, where this TM setup wouldn't work, at least for very long. One of my FCP projects during this time became a couple hundred GBs. Since TM sees the FCP Library as a single file, any edit/change resulted in the entire thing being backed up. So my FCP files get backed up differently. But the Final Cut Backups folder in my home directory (essentially the XML files - very small) still got backed up by TM.

 

[MalagLagoon]

Just to make sure I'm on the same page, you're not filling up you new MBP drive when you get it, right? I'm assuming nowhere close. But for me, I have a 2TB MBP M1 Max connected to a 2TB HDD TM. It's been backing up nicely for years. Because TM only backs up data, this first time, and data that as changed after that. There are certain apps, like FCP, where this TM setup wouldn't work, at least for very long. One of my FCP projects during this time became a couple hundred GBs. Since TM sees the FCP Library as a single file, any edit/change resulted in the entire thing being backed up. So my FCP files get backed up differently. But the Final Cut Backups folder in my home directory (essentially the XML files - very small) still got backed up by TM.

I plan to fill up the 8T on day one and expect everything to work flawlessly - just kidding.

Yeah, it occurred to me that if, say, I used only a forth of the 8T drive then I might be able to find an external hard drive or SSD that works. But, if I never intend on filling up my 8T drive - then why get an 8T drive at all?

8T seems a bit insane to me - at least from my POV - in 2025. I'd probably be alright with a 4T. Honestly, even 2T would be wonderful. I've been living with a 1T and it isn't enough when you consider using Parallels + media files.

I have FCP but most of my FCP files are usually between 2GB to 20GB. Yeah, I've got a few larger FCP files - not sure if I ever created a 200GB FCP file. I'm guessing no. I tend to remove the dead weight of large FCP files to storage. But, Time Machine is backing up whatever FCP files are on my internal SSD.

There is an argument for purposely keeping your internal SDD smallish. With a smaller drive you must perform regular housecleanings to organize and store your data. I'd hate to get an 8T and then see the disorganized mess I'd create 5 years down the road. On the flip side - if you always need to keep and extra 500GB free for FCP or some other application - having a roomier drive might be the way to go. Future proofing is another reason to get a larger SSD - despite the bilking from Apple.

At the moment and from my previous experience with Time Machine I feel that 4T is the biggest I could get without having to deal with a lot of fuss if not outright dysfunction from Time Machine complaining there isn't enough space. My experience is that you need an external drive that's larger than the SSD for Time Machine to work properly - at least in my case - for whatever the reason. Which might be due to FCP - don't know.