Coworker has an Acasis NVMe enclosure with a 1TB NVMe. Speeds are about 3000MB/s on USB4.

The thing is that he has lying around a 8TB HDD 2.5 from an old PC.

It would be awesome to use both as “Fusion drives” by connecting them to his Mac Studio M2. The question is if macOS Ventura supports this kind of arrangement.

He uses it for video editing. The idea is to copy source files overnight to the Fusion Drive and work from there instead of reading from the office NAS (local is fine with 2.5Gb, but WFH is unbearable at 150Mb~ tops plus latency).

2 Answers 2


It's possible: though I would advise against it.

Fusion Drives were a nifty use of CoreStorage a decade ago, when SSDs were limited in size and expensive.

Fusion Drives are designed to retain a small (4Gb?) part of the SSD for file transfers and general workspace, which would not be sufficient for large video files.

Fusion isn't magic, and once data is being written or read from the HDD portion, that's not going to be any faster than usual HDD speeds.

Also, remember that if one half of the volume is missing, the remaining half is meaningless junk. You've got twice the failure risk.

  • Good point. Seems that OpenZFS would be a better alternative. Commented Aug 9, 2023 at 19:22

I'm not sure a fusion drive would help in this scenario.
The fusion mechanism pulls the most commonly used files to the SSD & leaves everything else on HD. When fusion was invented, the expectation was for just some system files on a teeny 24GB SSD. I think they eventually stretched it as far as 128GB.

I'd be more inclined to put the 'raw' footage on the HD & the proxy data on the SSD. This would be full-speed working, just taking slightly longer at final export.

I also think having two external drives as a single fusion is a bit scary - one tiny USB connect issue & you break the fusion. It's like a RAID 0… no inherent backup or parity, data striped between two disparate media.

  • Good point. Seems that OpenZFS would be a better alternative. Commented Aug 9, 2023 at 19:22
  • Fusion started on 120 Gb SSDs on the 2012 Mini, and they reduced it to the tiny 24 Gb drives that could just hold the system on iMacs.
    – benwiggy
    Commented Aug 9, 2023 at 20:39
  • @benwiggy - ah, so other way round. By heck but they're slow, though. My folks have one. It's like waiting for xmas, every time you try to do something. ;)
    – Tetsujin
    Commented Aug 10, 2023 at 5:51
  • I bought the 2012 Mini on day 1, and it was brilliant to start with; but as it filled up, the speed dropped off. Some things were fast, but then you'd do something that wasn't.
    – benwiggy
    Commented Aug 10, 2023 at 7:12

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .