Storage will never be as fast as system memory–that’s just the nature of system architecture. But thanks to NVMe (nonvolatile memory express), SSDs can deliver such blazingly fast performance, the penalty of “going to disk” tends to be miniscule.
NVMe encompasses a family of specifications for how software talks to storage. It works over a number of transport methods, including PCI Express, RDMA, and TCP. Storage arrays that support the NVMe standard are the sports cars of storage, exposing super-fast storage media more directly and efficiently than any other mainstream method allows.
Source:: Network World – Data Center