Also the XBone Durango is half hUMA.. or half coherency set of the PS4, or more precisely I/O coherent
http://www.vgleaks.com/durango-memory-system-overview/
Yet... i get the feeling that none of those, not even PS4 that uses Garlic and Onion for the GPU mem operations, implements the full set of hUMA possibilities!..
http://www.vgleaks.com/durango-memory-system-overview/
Video encode/decode engine. System coherency
There are two types of coherency in the Durango memory system:
Fully hardware coherent
I/O coherent
The two CPU modules are fully coherent. The term fully coherent means that the CPUs do not need to explicitly flush in order for the latest copy of modified data to be available (except when using Write Combined access).
The rest of the Durango infrastructure (the GPU and I/O devices such as, Audio and the Kinect Sensor) is I/O coherent. The term I/O coherent means that those clients can access data in the CPU caches, but that their own caches cannot be probed.
When the CPU produces data, other system clients can choose to consume that data without any extra synchronization work from the CPU.
The total coherent bandwidth through the north bridge is limited to about 30 GB/s.
Yet... i get the feeling that none of those, not even PS4 that uses Garlic and Onion for the GPU mem operations, implements the full set of hUMA possibilities!..