10 posts were split to a new topic: SuperDuper 4 upgrade
I have 4 Samsung Drives: three 2 GB T-5s, one 2 GB T7, and a recently purchased 4 GB T9.
I am convinced by time that the backup drive needs to be twice the size of my internal drive.
I use CCC and with their SafetyNet ƒ, I think that it serves me best.
I backup nightly the internal drive to one of the SSDs, and then backup THAT SSD to my OLDEST T5. On Saturdays, I rotate out the drive used to backup the internal drive with another SSD, and then backup THAT SSD to the oldest T5. I then on the next Saturday do the same with the 3rd SSD.
The T9 stores backup files that HARDLY ever change, PLUS Historical files that have not change in years. Getting those files off of the rotated SSDs was the goal.
I also keep the same files that are on the T9 on two different mechanical hard drives that are old, but still working. My goal is to never loose a file, and this plan works for me.
Other companies SSDs, like SanDisk, did not prove as reliable nor as easy to work with as the Samsung SSDs.
I believe that others can say the same. If one of my mechanical drives gives out, I will replace it with a Samsung SSD and disassemble it, using its platters as coasters.
They are always a conversation starter!
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Plus, you get to play with the magnets! 
The size of the backup drive needs to be large enough to hold your data, plus room for incremental changes if you want to maintain a history (maybe via snapshots). Depending on how much data you have (probably isn’t completely filling your internal storage device), how much changes between backups, and how many historic snapshots you want to retain, the proper size of that device could vary by quite a bit.
But FWIW, I use the same rule of thumb. My Mac mini has 2TB of internal storage, and my Data volume has about 1TB of content. I back up to 4 TB HDDs, which works great for me.
I’ve considered buying 6 TB drives for future backups, but I don’t think I’ll need that much. But I may get them anyway, depending on what the prices are at the time.
That can work for you. The downside of any backup strategy is that you need to be able to actually do it.
Mine is simpler, but it’s worked well for me. I have three USB-attached HDDs. One is used for Time Machine, which makes the usual hourly backups. The other two are used for CCC-based backups. They are powered-off when not actually being used. I try to remember to make backups every two weeks, alternating between the drives. But I often forget, and end up doing it with more time in-between (but I always make a backup to each before any macOS upgrade, so I can recover if something blows up).
Since my Time Machine volume is large, compared to my data, I have its weekly snapshots going back to when I put the drive in service (May 2022). It has been able to satisfy all my needs to-date. The other two drives are for when it fails, if that happens before I end up replacing it.
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Thanks. I also like the Samsung drive and just ordered a T7.
Am I correct that “GB” means terabyte in my vernacular? GB is used enough that I feel I’m missing something.
Yeah. Right now decent flash runs around $160 for 1TB. Those Samsung Tx are heavily marked up because they went through the trouble of slapping that flash into a $20 case.
But to be fair, a 1TB Samsung internal SSD costs between $230 (Samsung 990, Samsung V NAND flash, PCIe Gen4x4, read up to 7,150MBps) and $360 (Samsung 9100 PRO, Samsung V NAND TLC, PCIe Gen5x4, read up to 14,700MBps).
Comparing a major brand-name component against random no-name parts is not a fair comparison. The no-name model will always cost a lot less, but you can’t guarantee anything about performance or reliability.
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Nobody was talking internal Samsungs or no-names actually. It was their T series of external USB3.1-capped SSDs that folks here were discussing. Since this thread is about backups, it makes little sense to look at fancy flash like a 990 PRO (hence referring to “decent” flash).
And sticking with the theme of this actual thread and what folks are interested in here, Crucial isn’t a random no-name part. $160 for exactly 1TB.
And there are a plethora of decent USB3 enclosures for $20+ rounding out the external package. The $230 T7 will not perform any better (how do I know this? well, we tested exactly these two side by side right here in the lab), it’s just a 25+% markup. Obviously, to some those ~$50 may be perfectly worth it for the convenience. Others, will prefer to buy flash and enclosure separately and put the savings toward more capacity (eg. 2 TB instead of 1 TB runs about an extra $100 right now).
You’re comparing apples and oranges.
You’re claiming that a Samsung T-series external is a $160 internal SSD plus a $20 case, and all the rest is markup.
But Samsung isn’t shipping Crucial products. They’re including Samsung parts, which cost more.
No. The comparison is between what customers can buy delivering comparable performance over USB3 as external drives. Not more, not less.
Oops. Yes! Definitely 1TB.
Depends on the enclosure. I know there are very inexpensive enclosures but, for example, an OWC enclosure for that SSD runs around $70-80.
Note those more expensive enclosures are usually TB4.
And while you definitely want that if you’re doing real work with the drive and need to exploit all its performance, drives like the Samsung T7 do not support that. On a Mac, the best you’ll see with a drive like the T7 or even a T9 is USB3’s ~ 1 GB/s, which is perfectly fine for backup. But the point is, if you want to compare such a USB3 drive with a flash+enclosure combo that you put together yourself, you don’t need to buy flash that performs way beyond the bottleneck of USB3. The enclosure itself also can also be just plain USB3 — especially for just backing up. And those USB3 enclosures are readily available in all shapes and sizes for ~ $20. As always, it’s important to make sure you spec these things in a balanced manner: no use paying a lot extra for flash performance that gets bottlenecked by the bridge/bus, or buying a fancy TB5 enclosure for an NVMe stick that will only being doing TM (which has its i/o capped at about 300 MB/s).
Now full disclosure, me personally, I will usually still opt for TB4 even for backup, but that’s just because I don’t mind spending an extra $15 on the case in order to get SMART support which on a Mac you don’t if the flash interfaces over USB3. I will always mix and match myself, but if I were to get a preconfigured all-in-one drive, I’d therefore probably opt for something like an OWC Express (silly expensive IMHO compared to DIY).
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Helpful information. Full disclosure, I did go with the T7, which arrived today. No fuss, no muss. But here’s my question. AFAIK, this iMac has four TB4/USB3.2 ports on the back. However, am I to assume that those ports default to USB 3.2 or 3.1 when the external device is a USB 3.2 / 3.1 device? The T7 is not TB4. The OWC Express case, I believe, is TB4, but costs about $80. However, as you state, confirming my own belief, I don’t really need 40 GB/s for a conventional backup (of about 180 GB of data, including the OS). Are external TB4 devices uncommon, even today? Or simply a lot more expensive? The whole TB / USB thing I’ve always found a bit confusing. At least they use the same physical connector.
They will default to 10 Gbps USB 3.1.
This is also why, on a Mac, paying extra for 20 Gbps 3.2 over 10 Gbps 3.1 does not make a whole lot of sense. On a Mac, it’s 10 Gbps (or below) for everything USB that is not USB4. If you want 40 Gbps, you need to go TB4/USB4 or TB5.
USB 4 Version 1 nominally supports speeds as high as 40 Gigabits per second (Gbps), not 40 Gigabytes per second (GB/s).
At 8 bits per byte, 40 Gbps is 5 GB/s. When you factor in protocol overhead and other factors, “real world” USB 4 transfer speeds typically are around 30 Gbps.
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I apologize. My Samsung “T” drives are terebytes, not gigabytes……… Brain fart!
After formatting the T7, I used SuperDuper to make an initial backup. The new interface is quite a pleasant change. For the first backup, I chose to do an erase then create a bootable backup, which involves some additional overhead in prepping the drive. To make a long story short, average speed appeared to be about 550 MB/s for the duration of the process, which lasted about 10-12 minutes in total. That includes the preparation of the drive, the backup, then creation of a bootable backup. Nowhere near the maximum speed of the port but I assume there was a fair amount of overheard involved. Subsequent copy jobs should be faster.r Be that as it may, 10-12 minutes isn’t bad, Then again, there is only about 185 GB of data on the internal SSD.
Further question: I thought modern Macs could not be booted from an external device? What exactly does '“bootable” mean here? (SuperDuper indicates that some system, et cetera., files will not be backed up.)
They can, but it works differently from the pre-Apple Silicon days.
The most important difference is that the boot process always starts from the internal flash (SSD), no matter what drive you want to boot from. That flash memory is where the “firmware” and iBoot boot loader reside. If that internal flash becomes corrupted or i/o to it fails (e.g. logic board issue), you cannot boot that Mac at all anymore. At best, you have to use another Mac to flash the internal drive and set it up from scratch with a new firmware and new macOS. At worst, Apple will have to swap the flash daughter card (Mac Studio) or swap the entire board.
Another consequence of the boot process always starting from the internal flash is that an external drive that is intended for booting that Mac, has to be “blessed” to boot up that Mac beforehand. Basically that process (the Local Policy system) tells the boot system on the internal flash that this external drive is kosher and should be allowed to boot up that Mac. That requires, when setting up the external system, authenticating with a user/pass that has an admin account on the system of that internal flash (lots of great detail on this courtesy of Howard Oakley right here). So you cannot just take any macOS install on any drive, hook that up to a modern Mac, and expect it to just boot. That indeed no longer works. Instead, when you set up the external drive, you have to, in a sense “pair” it with the system on the internal flash. That way that system will know this is a vetted install that can be allowed to boot this Mac. This is basically a consequence of the modern security paradigm that actually predated Apple Silicon (recall, any T2 Intel Mac would not default to allowing just any disk to boot, you actually had to open up a firmware option to enable that).
A final important consequence of this new model, is that the boot system is no longer just a regular partition with an installed macOS. It’s these days the SSV that is a cryptographically sealed specific macOS install. An image of that gets mounted at every boot to load the macOS system and most of its built-in apps (Safari being one of the few and well known exceptions). A consequence of this is that every single Mac out there right now booting a certain version of macOS, will be running the exact same system, down to the bit. What this also means is that for folks using clone tools to make a backup of their Mac, this part in principle does not have to be backed up. For one, because it never changes (as long as you do not update macOS), for another because there is always another backup copy of that (in some cases actually two, but then often not of the same vintage) already stored on another partition (restore) of that Mac, and finally, this part can always be re-installed down to the exact bit just by re-installing macOS either from an installer or over the internet, since this SSV is static and locked down so nothing you would ever configure or change resides there. That all said, if you want a truly bootable backup, the backup tool needs to still include that SSV in spite of its redundant nature, since it is required to boot a Mac. So this distinction is primarily important for users looking to just clone as in backup (to later for example play back via Migration Assistant) vs. users looking to clone to something that shall be able to independently boot that Mac.
So short answer: modern Macs can boot off of external drives. It just takes a bit more effort than it used to in order to ensure security remains as tight as possible.
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