The Cisco HyperFlex deduplication chunk size based on the underlying block size of a data object. This means the deduplication chunk size can be 4K, 8K... 64K, depending on whatever the block size is you chose when creating the data object (eg. VMDK).
Cisco, HyperFlex [HCI]/4.0, x86
Dedup/Compr. Granularity, Efficiency, Data Services