Enable RDMA over Thunderbolt in macOS 27

I explain the new macOS 27 setting for enabling RDMA over Thunderbolt, a feature relevant to people clustering Macs with Thunderbolt 5. The setting brings an option previously enabled through Safe Mode and the command line into Settings.

- How RDMA supports low-latency communication and sharing model workloads across Macs
- Where the new macOS 27 setting fits in a Thunderbolt 5 cluster setup
- The change from the previous Safe Mode and command-line process

This overview is for Mac users working with Thunderbolt 5 clusters. Check Settings on a compatible system to see the new option; detailed setup instructions and performance testing are not covered.