Remote Direct Memory Access

Remote Direct Memory Access (RDMA) is a communication method where one computer directly reads and writes data to another computer's storage space. Normally, sending something to a neighbor requires going through a mailbox—checking it in, then taking it back out. RDMA skips that process entirely, more like directly opening the neighbor's storage door and taking the item out yourself. With the intermediate checking step gone, things move much faster, and the part of the computer that acts as its brain doesn't need to stay tied up handling that work.

When this method is applied across multiple machines at once, their individual storage spaces can be joined together like one giant warehouse. So if several computers are connected with fast cables and use RDMA, work too large for a single machine to handle can be split across multiple machines and processed as if they were one unit.

In the article, it's used like "supports Thunderbolt 5 and RDMA, allowing multiple units to be tied together into a single memory pool." It's easy to mistake RDMA for simply 'a fast cable connection,' but the key point isn't speed itself—it's direct access to another device's storage space without intermediate checking steps. The cable is just the pathway through which that access travels.