Time for an SSD for Time Machine

TidBITS Talk
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So I feel like SSDs have finally become cheap enough so I’m no longer going to even bother with HDDs for TM. Since this is for TM, I’m assuming a SATA-III interface is just fine (don’t need the added speed of PCI-connected SSDs), a simple USB-C dock will provide an inexpensive connection to the Mac. I’m aiming for 2TB.

There’s great such SSDs that have become really affordable like the Samsung 870 QVO. $213 for 2TB.

https://www.amazon.com/dp/B089C73T72

I do wonder though, this SanDisk is substantially cheaper. 2 TB for just $189, and every once in a while this drive will be discounted to $180 or less. Can anybody say something really bad about this disk? It definitely sounds like a very inexpensive TM option.

https://www.amazon.com/SanDisk-SSD-PLUS-Internal-SDSSDA-2T00-G26/dp/B07YFFJK2Q

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G’day Simon

Don’t know the two drives you’ve linked to.

However, re SSD – I’ve been using a set of Samsung 500GB T5 drives since 2017 for both Time Machine and Carbon Copy Cloner bootable backups via USB-C/USB 3.1 Gen 2.

CCC ones are APFS formatted, subsequently encrypted via File Vault. TM ones are formatted Mac OS Extended (Journaled, Encrypted)

Backing up to them is swift, as is restoring/ booting from.

The T5 has recently been superseded by T7 so shops here (New Zealand) have had the T5s on clearance at very attractive prices. Presume it’ll be similar where you’re located. If you’re interested in the newer T7s, be aware there are two versions; standard and fingerprint encrypted, the latter obviously more expensive

Cheers, Gobit

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I opted for the 2 TB Samsung T7, which costs a bit more than what you found (with tax, it was $345 from Amazon). I chose it in part on the industrial design and good reviews—with a backup drive, I’ll often pay a little more for a perceived increase in reliability.

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I’m focusing on the bare drive here. I usually never buy combined units. I prefer to buy drive and enclosure separately, and I frequently mix and match later on. I have plenty of decent enclosures ready to go, just looking for a new drive that I’ll use along with a Big Sur system.

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There is a slight risk with using SSDs for long term archiving. Way back when affordable SSDs first appeared I came across articles claiming that they needed to be powered up once in a while (maybe every few months) to avoid loss of data. I would be interested to know if this is still the case.
Of course most archiving options have long term uncertainty: DVDs & hard disks maybe a decade, Blurays maybe 30 years…(when Bluray readers will only be in museums).

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What I have done for Time Machine backup in my MacPro 7.1 2019 Tower is installed a 2 drive Pegasus Promise cage with 2 8TB hard drives. Since I do not require 8TB for backup I soft partitioned them into 2 - 4TB drives and mirrored Time Machine to them by soft RAIDing them via Disk Utility so that backup are simultaneously backed up to both of the 2 drives. That way if one drive ever fails, I likely will still have a fully accessible backup on the other drive. The remaining partitions on both drives are also mirrored via soft RAID and contain active files of critical data such as finances, music, photos, and videos which do not require the speed of an SSD… So if one drive should fail, nothing will be lost. In place of the normal folders in my user account, I have replaced them with symbolic links to the Pegasus drives. This has work for me for many months using Catalina. I discourage users from using SSD’s for backup’s as they are engineered to eventually fail as they have physical limitations of the number of read/writes they can handle before failing. The only advantages that SSD’s seem to have for me is size and speed, of which neither one is necessary for long term storage/backup. The Pegasus Cage comes with an 8TB drive already installed so the only additional expense was a second 8TB drive at around $200 which makes this an effective cost saving solution over SSD’s. Given the current price point of internal 8TB drives and the cost of cases to interface to them, it also makes them an effective cost saving solution for other backup solutions as well, especially where high speed performance is not necessary but long life is needed.

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This drive has just dropped in price again. Now $180 for 2TB.

It was once briefly at $160 though.
https://camelcamelcamel.com/product/B07YFFJK2Q

Meanwhile the 870 QVO increased just a little bit to $216 for 2TB.
https://camelcamelcamel.com/product/B089C6LZ42

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I’ve heard the same thing. It shouldn’t be a problem for Time Machine, however. TM’s main purpose is for regular, hourly, backups, not archives.

For long-term storage archives, I would definitely recommend something else - either tape (if you can afford the drive) or hard drives.

These are frequently-quoted figures, but my experience disagrees completely.

Magnetic media, if properly stored, can last for an extremely long time. Far longer than 10 years. For example, I’ve got Apple II floppy disks that are still perfectly good after nearly 40 years.

Optical media longevity depends greatly on how it was manufactured. I’ve got some CD-R and DVD-R media that failed within months of burning. I’ve got others that have lasted for over 10 years. Unfortunately, there is really no way to know in advance if the media you’ve got will last or not. Manufacturer claims have not been reliable.

I think a bigger problem is if your drive (including the mechanical parts of a hard drive) will last that long or if you’ll still have a computer that it can connect to. It’s already impossible to get a new floppy drive, or tape drives for older standards like DAT, Travan and VXA. Even optical drives are are going to be going away (hopefully not too soon), since software manufacturers don’t generally distribute their products on disc anymore and a very high percentage of consumers prefer downloads and streaming for their music and movies.

Furthermore, modern computers may not have the interface required to connect drives for these older standards. For example, I’ve got an archive of old Mac software on SyQuest cartridges. I have a working drive, but the most recent computer I’ve got with the SCSI port it needs is a 2002 PowerMac. Anything you buy today will probably end up in the same situation 10-20 years from now - don’t count on even USB being available then.

In other words, there is no good choice for archival storage unless you’re prepared to do the work needed to migrate your archives to newer media as old formats go away and new formats are invented. But this discussion is far beyond the scope of whether an SSD is or is not a good idea for Time Machine.

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I have similar (good) experience with magnetic media…
Before CDs I used Zipdisks (~100Mb) and a couple of years ago I needed to recover some data from the 1990s. I managed to find a zip drive for sale on ebay. To my surprise it worked on my Mac (USB) and, even more surprise, I could successfully read nearly all of the zip disks. Needless to say, I copied their contents to the Mac. But we digress …
I think I mentioned in these discussion a few years ago that a sci-fi novel suggested “long term” archiving by carving symbols into the walls of a cave on Pluto!

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A non-fiction example of this is the Long Now Foundation, whose goal is long-term archiving (as in for the next 10,000 years) of human knowledge.

It’s pretty fascinating to read about their projects and the thought processes involved. For instance, you can’t expect any particular kind of computer (or power source) to exist that far into the future, so you’re doing things like storing data by etching microscopic printed text on metal discs - which can be read by anybody with a microscope-like device. You also can’t assume that any language spoken today will exist then, so one of their first projects is to archive a global linguistic database that (hopefully) will allow those future people to be able to read the content we’re archiving.

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The Samsung QVO 870 can now be purchased for just $199 for 2 TB. Lowest price ever AFAICT.

https://www.amazon.com/dp/B089C73T72

https://camelcamelcamel.com/product/B089C6LZ42

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Note that QVO drives use a relatively new technology that results in lower cost, performance and lifespan. Here’s one site’s comparative outline: Samsung QVO vs EVO vs PRO: What’s the Difference?.

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For a TM drive I’m personally not too concerned because my drives tend to fill up rather quickly and then get swapped. It’s correct that TM does a lot of reads and writes, and that is definitely an issue on a QLC drive. However, if the ballpark estimate for life cycle is about 1000 r/w operations (or program/erase as is technically more correct), I estimate that’s still 1-2 orders of magnitude larger than what one of my typical TM drive reaches till I fill it up and swap it out. The next concern would be long-term storage, but again, that’s not what I’d use a TM drive for.

I think the lifetime issue would primarily be a concern for somebody who tends to use one TM disk for a very long time, i.e. throwing out older snapshots to make room for new ones. If that is a concern, MLC would definitely be more advisable, of course at a cost.

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The following posted 11.18.20 to the Mac-L (if ACE doesn’t object %-)>) by Randy Singer, author of The Macintosh Bible:

Hard drive recommendations
Lots of very useful advice and recommendations from Bombich Software, =
makers of Carbon Copy Cloner:

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@berndt thank you for a fantastic link. That article is so clear and complete - just saved me some $$ because I was about to order a drive they would not recommend. Once again TidBITS contributors have come to the rescue!! Learned a lot from this conversation. I’m not terribly bright and I’m sure not rich so this has been extremely helpful.

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