For concurrent I/O, how are Endurant Cache and SmartCache different?

A.
Endurant Cache sends an acknowledgement to the client immediately after mirroring writes in NVRAM

B.
Endurant Cache waits for acknowledgement from allnodes before copying to L2 cache

C.
SmartCache immediately commits the write to NVRAMon the local node and one peer node

D.
SmartCache uses sub-file, granular locking whereas Endurant Cache locks the entire file