Can the Pegasus R4i be installed and used in the new Mac Pro 2023

  • Last Post 16 July 2023
Alexander Hafemann posted this 06 June 2023

As yesterday Apple announced the new Apple Silicone Mac Pros with PCI Slots, i`d like to know if it is possible to use the Pegasus R4i MPX Module in the NEW MAC PRO 2023.


I`d like to see an option to use the MPX Pegasus R4i in the new Mac Pro 2023 ff..

Thanks for any help or information.


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R P posted this 06 June 2023

Hi Alexander,

The 2023 Mac Pro has 6 gen4 PCIe slots, but it has no MPX slots, which are special PCIe slots for the R4i and video cards. The MPX slots provide additional power for use by the Pegasus R4i and Mac Pro video cards. The 2023 Mac Pro has no MPX slots and don't support the use of a Pegasus R4i.

However the Pegasus J2i can be installed in the 2023 Mac Pro.

EDIT: It might be possible to use the Pegasus R4i with a TB to PCIe adapter. There are several on the market. This has not been tested and it may or may not work.

EDIT2: A Thunderbolt to PCIe adapter cannot be used as it cannot provide extra power to the Pegasus R4i as an MPX slot does.

John Bergin posted this 16 July 2023

I picked up a Mac Pro 2023 a few weeks after they became available. At the time, Apple said the R4i was compatible with the 2023 Mac Pro. Having an R4i in my 2019 Mac Pro, I was glad to hear I could just pull the R4i and slot it into a new 2023 Mac Pro. Apple (and Promise) have since updated their specs to reflect the fact that this is not the case. I guess I was one of the first people to discover the R4i is not compatible with 2023 Mac Pro.

My question: Does Promise have plans to release an R4i that is compatible with 2023 Mac Pro? The R4i is by far the best bay I've ever owned. Massive storage space, dependable, and completely SILENT. I'd purchase one for my 2023 Mac Pro in a heartbeat.