External SSDs keep getting ejected on MacBook Pro

Hi all,

I’m trying to utilise a mid-2015 MacBook Pro to plot. I bought 2 NVMe SSDs and 2 USB-C enclosures. MacBook Pro only has 2 USB 2 ports. I’m plugging in the enclosures with a USB - USB C adapter.

It’s taking too long but since it’s not my primary rig I’m ok with getting a few plots every now and then. The annoying thing is after spending many hours, all of a sudden both USB drives get ejected at seemingly random times. I tried with 1 drive but same result.

Disabled putting disks going to sleep and power nap in power settings but still to no avail.

Do you know any cure for this issue I’m having or any tips for me to troubleshoot it?


I have found if it is a high power draw USB device, you’ll see these kinds of problems, unfortunately :disappointed:

I have real trouble finding machines that can power a 980 Pro 2tb in an Orico enclosure (ASM2364 chipset, the best and newest 20gbps one).

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Ah, power! Thanks, @codinghorror. Now makes more sense.

I dug up a 12-year-old powered USB hub. Let’s see if it helps. I’ll post here the results.

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Powered USB didn’t work. Maybe because it’s too old. SSD inside the enclosure is getting too hot. I’m using this enclosure: https://www.amazon.com/Sabrent-Type-C-Tool-Free-Enclosure-EC-SNVE/dp/B08RVC6F9Y/

I’m now trying a new run with the enclosures lid open. Not very hopeful but at least doesn’t cost anything to give it a shot.

I’m looking to buy a powered enclosure now but I haven’t been able to find such a product yet.


I can recommend these little USB powered 120mm fans, they’re very handy to have, can be daisy chained, and even come with a little AC adapter if you want to power them off a wall socket:

Basically “put a USB powered fan anywhere you want”… really fun item. Safe too with the grills and the rubber baby buggy bumpers on each corner… :baby:


Cool (literally and figuratively!). Looks like they can handle my heating issue. Thanks for the recommendation. Checking it out now.

I am having an interesting issue that is very similar.

I have two Mac Mini M1s, each with a Samsung 980 in an Orico NVME enclosure connected via Thunderbolt.

One Mac Mini works great - the other regularly disconnects.

I know it sounds like a hardware issue but would be interested to hear any ideas for troubleshooting if anyone has them :slight_smile:

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Hey @durin, did running them with the enclosure lid open help with this problem?

Interestingly it never ejected the drive with lid open and all plots since then have been successful.

The thing is the USB-hub is slow a single plot takes about a day. So I’m not entirely sure at this point if opening the lid or slowing down the process did the job. Maybe it’s a combination of both.

I ordered a new powered USB 3.0 hub. I’ll see if it still works with faster USB hub.

Ah I see, I have Thunderbolt enclosures which is a little different. That may actually make things worse as there’s probably more data flowing through them and they’re working harder?

I wouldn’t say worse as you’re getting more value for your money.

I believe in my case, USB hub is the bottleneck so SSD is not used to its full potential. I’ll see if USB 3 hub makes any difference.

I can run more experiments but given the current growth of the netspace it also feels kinda pointless. My chance to win is receding everyday even though I’m creating plots at full capacity. 1 plot more or less is not going to make a big difference.

Have you considered asking the SSDs nicely to just not?


Ah I knew I forgot something!. Thanks, I’ll try that now :slight_smile:

I think that is a very logical philosophy. Every time I’ve been impatient with Chia plotting and have pushed it too hard, I’ve ended up either losing plots or losing many hours of time. Better to scale horizontally (more machines) if you want more tb/day.