Raid-10 on an Icy Box IB-3740-C31 – 4-bay USB-C case

Just got an Icy Box IB-3740-C31. Packaging was thankfully good as it was not delivered in a brown box around it.

Adding 4 SSD drives was a bit of a fiddling, but once the two screws per drive were attached and the sliders were in the case it was fine.

Starting up, all 4 SSDs were directly detected by my MacBook Pro.

Noise level is not super silent but ok, maybe I switch the fan later on.

Setting up a RAID-10 with Apple Disk Utility

In Disk Utility, go to File > RAID Assistant…

Who would know that once you have 4 drives you can’t just create a RAID5 with the disk utility? The only obvious options are RAID0, RAID1 and JBOD.

But there is a trick here if you want to use the RAID Assistant. Just create a RAID-10 out of 2 RAID-1 combined by a RAID-0.

First, we create a RAID-1 with 2 disks:

For my use case I used the largest block size and named the first RAID-1 raid1_1.

Then I did the same steps again with the second two disks, named it raid1_2.

Now as you have 2 RAID-1s, it makes sense to combine them to a RAID-0 – set the same block size and works fine. Named it raid10 (finally).


  • If you have 4 drives you get 50% of the capacity (e.g. 4x 1TB -> 2TB to use)
  • up to 2 drives can fail here and it would still work (1 on each RAID-1)
  • better fault tolerance than a JBOD
  • fast(mirrored & striped) compared to JBOD, single drives
  • a lot cheaper than a NAS
  • faster than a NAS with up to 10 Gbit/s via USB3.1 (Gen2, UASP)


  • a software raid on top of another software raid, not sure yet if you can move it between macs?
  • RAID-5 would give you 75% of the capacity (e.g. 4x 1TB -> 3TB to use), but only one drive can fail there
  • Only attached to one computer compared to a NAS – but possibly more speed


The Icy Box seems to work fine so far, and it feels quite fast (no scientific test/speed runs here) to copy large files around – it’s definitely a lot faster and responsive than the NAS in the same room. Looking forward to video editing on it.

Would have loved to go with a RAID-5 but for now I can always use the provided system tools.

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