In NUMA, does each CPU also has local I/O controller similar to local RAM?

Question

In Non-uniform memory access, does each cpu has it's own I/O controller? I understand that in NUMA, each CPU has their local RAM. It's like each processor is running an individual process. They can speak to each other using IPC mechanism like Socket, etc. I was just wondering just like each local RAM, do they have local I/O controller as well?

Answer 1

Nodes in a NUMA system have local RAM and can have local I/O. The later depends heavily on how the system is configured at the hardware level. If memory interchanges are performed by I/O accesses, then obviously each CPU must have its own I/O controller.

Here you have an example of an (old) NUMA system with local I/O for each node: http://lse.sourceforge.net/numa/older_stuff/meetings/mtg.2001.07.25/minutes.html

Answer 2

The answer is No. However, different hardware generations might have different architectures. please see the following for architecture diagrams which might help answering u'r question:

NUMA diagrams