Upgrading an M4 Pro Mac mini's storage for half the price

The article speculates on why Apple integrates the SSD controller onto the SOC for their A and M series chips, but misses one big reason, data integrity.

About a decade and a half ago, Apple paid half a billion dollars to acquire the patents of a company making enterprise SSD controllers.

> Anobit appears to be applying a lot of signal processing techniques in addition to ECC to address the issue of NAND reliability and data retention. In its patents there are mentions of periodically refreshing cells whose voltages may have drifted, exploiting some of the behaviors of adjacent cells and generally trying to deal with the things that happen to NAND once it's been worn considerably.

Through all of these efforts, Anobit is promising significant improvements in NAND longevity and reliability.

https://www.anandtech.com/show/5258/apple-acquires-anobit-br...

> The article speculates on why Apple integrates the SSD controller onto the SOC for their A and M series chips, but misses one big reason, data integrity.

If they're really interested with data integrity they should add checksums to APFS.

If you don't have RAID you can't rebuild corrupted data, but at least you know there's a problem and perhaps restore from Time Machine.

For metadata, you may have multiple copies, so can use a known-good one (this is how ZFS works: some things have multiple copies 'inherently' because they're so important).

Edit:

> Apple File System uses checksums to ensure data integrity for metadata but not for the actual user data, relying instead on error-correcting code (ECC) mechanisms in the storage hardware.[18]

* https://en.wikipedia.org/wiki/Apple_File_System#Data_integri...

> If they're really interested with data integrity they should add checksums to APFS.

Or you can spend half a billion dollars to solve the issue in hardware.

As one of the creators of ZFS wrote when APFS was announced:

> Explicitly not checksumming user data is a little more interesting. The APFS engineers I talked to cited strong ECC protection within Apple storage devices. Both NAND flash SSDs and magnetic media HDDs use redundant data to detect and correct errors. The Apple engineers contend that Apple devices basically don't return bogus data.

https://arstechnica.com/gadgets/2016/06/a-zfs-developers-ana...

APFS keeps redundant copies and checksums for metadata, but doesn't constantly checksum files looking for changes any more than NTFS does.

That solution doesn't help anyone who's using external storage, though, so it kinda feels like a half billion dollars spent on a limited solution.

Apple does not care about external storage at all, as in external disks. They offer iCloud for external storage. They don't sell external disks. They don't like cables. They make lots of money selling you a bigger internal disk.