Networks

A cluster only acts as one computer if its chips can swap results fast. Scale-up is the very fast network inside one rack or pod, such as Nvidia NVLink or AMD UALink. Scale-out connects racks to each other, usually over InfiniBand or Ethernet, the common networking standard. A third tier now links whole data centers, like Microsoft's AI WAN.

Gb/s is gigabits per second and GB/s gigabytes per second; one byte is 8 bits. The cards below each come from a sourced page.