iMac Pro - using three Thunderbolt 3 ports for build RAID 0 with external SSD PCIe

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Level 1

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iMac Pro - using three Thunderbolt 3 ports for build RAID 0 with external SSD PCIe

I bought three external Thunderbolt 3/4 boxes (40Gbps) with 3 SSDs NVMe PCIe. Boxes solo works very well and every from the disks operates very fast. BUT when I connect all three boxes in same time I see connected only two from disks. I tryied to change cables, to change connected ports but everytime with same result. Can someone help me please how can I to connect three external boxes via Thunderbolt 3 on iMac Pro and build RAID 0 from there? Thank you in advance.

iMac Pro, macOS 15.7

Posted on Nov 21, 2025 3:53 AM

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Answer 1

den.thed

Level 10

90,652 points

Nov 21, 2025 8:59 AM in response to deedee444

Sounds like the iMac Pro's TB bus can not supply enough power for all three drives at the same time.

What brand and model are the TB 3/4 boxes..?

Why do you want to create a RAID 0 with these external drives..?

IMHO a RAID 0 setup with external drives is asking for failure and total data loss.

Think about it, if one drive fails to connect or has a problem, then you loose everything.

If I was to choose a RAID setup, it would be RAID 1 with two drives and then rotate in the third drive.

Or better yet, use a single drive for whatever and then use the other two drive for rotating CarbonCopyCloner clones.

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Answer 2

den.thed

Level 10

90,652 points

Nov 21, 2025 10:28 AM in response to deedee444

deedee444 wrote:

Hi den.thed thank you for a very fast reply.

You're welcome.

I am using boxes ACASIS TBU405 Air with Lexar NM790 2TB ssd inside. This RaidO I need for specific Premiere Pro projects where I used a little complicated web of sequencies. So i need very fast reading of video files. I am used to backup every step of my work because of loosing some parts of my works in tha past.

The RAID 0 thing worked great to increase the speed across HDD's. I'm not an expert in this area, but a single NVMe SSD in a TB 4 enclosure is already around 20 times faster than HDD's in RAID 0.

I find one tutorial on YouTube how to build RAID0 via Thunderbolt ports and I looked forward for an solution about my complicated projects without buing other expensive tools..

If you insist on a RAID and reliability, you should use a 4 bay TB RAID enclosure instead of using separate enclosures.

for example > https://www.owc.com/solutions/express-4m2

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Answer 3

deedee444 Author

Level 1

4 points

Nov 21, 2025 9:27 AM in response to den.thed

Hi den.thed thank you for a very fast reply.

I am using boxes ACASIS TBU405 Air with Lexar NM790 2TB ssd inside. This RaidO I need for specific Premiere Pro projects where I used a little complicated web of sequencies. So i need very fast reading of video files. I am used to backup every step of my work because of loosing some parts of my works in tha past.

I find one tutorial on YouTube how to build RAID0 via Thunderbolt ports and I looked forward for an solution about my complicated projects without buing other expensive tools..

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Answer 4

deedee444 Author

Level 1

4 points

Nov 21, 2025 2:35 PM in response to den.thed

Thank you for your solution but it is still one device of 40Gbps speed and my intention was to multiply speed of more 40Gbps devices. Every my project have few Tera Bytes of datas. So if I move cursor on timeline I need realtime preview - and this is exactly speed of data reading. Of course it is question of video codecs also but as I am using Apple is logical that I am using formats and codecs best for Apple processor. If would be some option how to put more energy power via thunderbolt for 3 external SSDs devices I would aprecciate it.

And thank you for your time to help me with my problem.

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Answer 5

deedee444 Author

Level 1

4 points

Nov 21, 2025 10:19 AM in response to den.thed

Please you think is any software solution to put more power for thunderbolt ports?

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