Capacity limits for external hard drive enclosures

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Level 1

26 points

Capacity limits for external hard drive enclosures

I've been given two identical, sturdy and particularly well-finished hard drive enclosures to use for external storage. I suspect they are in the range of 10 or so years old. There is no identification of the manufacturer, nor any model or part numbers on the outside of either; only an unfamiliar graphic logo nicely marked on the metal case.

The enclosures contain hard drives which are small by today's standards, 320 and 500 GB respectively, but both seem to function normally. My intention when accepting the enclosures was to install new larger drives, likely 3 or 4 TB.

I had no problem opening one of them; it contained a Western Digital Caviar drive dated 2009. Swapping in a new 3 TB drive with about 400 GB of data already stored was easy; it showed up properly in Finder. Disk Utility suggests all is well: shows 4.07 GB used, 2.69 TB free.

My questions are:

• Do older enclosures like this have a limit on the capacity of the drive that the enclosure will support, based on the electronics in the device?

• If the answer is "maybe," then do I have to attempt to transfer a large amount of data to find that limit?

Or does Disk Utility info tell me all I need to know?

Mac Pro, OS X 10.11

Posted on May 10, 2022 12:23 PM

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Answer 1

HWTech

Level 9

68,306 points

May 14, 2022 6:08 PM in response to tytoalbaow

Yes, enclosures can have limits on the size of the drives that can be used which is due to the SATA controller chip used by the enclosure (same thing for USB SATA adapters & drive docks).

Some enclosures will have a 2TB limit, while others may have a 4TB limit.

Hard drives larger than 2TB also present the block size differently than older drives 2TB and less, but some of the more recent drives may no longer offer this older compatibility mode of presenting the block size as 512 Bytes. Many current drives will now only present the block size as 4K. Even if a drive has an option to present itself with 512Byte blocks, not all SATA Controller chips or operating systems can handle it.

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Answer 2

HWTech

Level 9

68,306 points

May 15, 2022 11:55 AM in response to tytoalbaow

Unfortunately only enclosures made after the changes were implemented are likely to have any mention of size limitations in their documentation. If you use a drive that is beyond the size limitations of the enclosure, then the drive will usually show up with a much smaller size in Disk Utility and you won't be able to properly read the data on the drive.

As far as purchasing new enclosures today.....make sure to check the documentation before purchase. Vendors will sell anything ...even tech that is outdated.

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Answer 3

ku4hx

Level 7

23,688 points

May 15, 2022 1:13 PM in response to tytoalbaow

Decent USB enclosure can be had for around $10-$12US. I like a bargain too, especially if it's "free". However, the tech is still very old, Dinosaur old in tech years, and the conditions they were stored under are complete unknowns.

If it were me, I'd thank the individual and then get a couple of new ones.

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Answer 4

Phil0124

Level 10

216,482 points

May 10, 2022 12:40 PM in response to tytoalbaow

No. The enclosures themselves do not have any limitation when it comes to the hard drive size. It's just a passive connection.

Yes, Disk Utility will tell you all you need to know.

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Answer 5

tytoalbaow Author

Level 1

26 points

May 15, 2022 2:29 PM in response to ku4hx

ku4hx:

Decent USB enclosure can be had for around $10-$12US

Where?

What seller could be less than half the price from Amazon?

I bought a cheaply made enclosure from them two weeks ago for $28. Haven't used it yet.

As for the two well made ones I was given: I installed the new 3TB drive a week ago and it's been just fine. As stated previously, it shows the correct capacity amount used and available.

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Answer 6

tytoalbaow Author

Level 1

26 points

May 14, 2022 8:42 PM in response to HWTech

Thank you HWTech;

I mostly understand the first point in your reply, but the second left me with a question. Well... several questions!

Some enclosures will have a 2TB limit, while others may have a 4TB limit.

How do I determine the limit on any given enclosure? WouId there be specs from the manufacturer stating that limit?

Or will I only discover that by "trail and error" after I've begun transferring large files and somewhere midway in the process, after most of my data is transferred, there's an error message mentioning the 2TB limit and somehow makes the entire transfer wasted time?

Given what's happening with hard drive size recently, is it likely that the capacity limit on recently manufactured enclosures is much higher than drives from 10 years ago?

If Disk Utility tells me there'a a certain capacity available for a specific enclosure and the disk I've installed in it, is that a reliable indicator, as Phil0124 suggested?

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Answer 7

tytoalbaow Author

Level 1

26 points

May 10, 2022 12:49 PM in response to Phil0124

Thank you Phil0124 for the quick and clear answer. I'll proceed with my intended plan, I'm glad that these nicely made enclosures will be useful.

Tyto

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Capacity limits for external hard drive enclosures

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