The much lower latency of the new gcs have higher demands on runtime data-structure in terms of latency.
We must create new data-structures to accommodate this and apply them on latency sensitive data-set.
The hashtable should be able to do all operation with little serialization between threads. 
A highly concurrent hashtable will require a way to handle ABA without locks, such as hazardpointers, RCU, type-stable-memory.