Faster or lower latency? Right now traditional SSDs are extremely high bandwidth when transferring sequential files (approaching 3.5gbyte/s read and 3gbyte/s write) but they lack the random 4k IOPS to lower the perceived latency on disk.

Intel's Optane is the first consumer SSD I've seen that has high performance 4k read write IOPs not unlike memory, but even if you use that as your boot drive we are starting to put pressure on other part of the system. Soon the SSDs will start to have higher performance than their PCIe 3.0 x4 slot and some already need a x8 slot when striping nvme SSDs.

Take a look at https://www.anandtech.com/show/12951/plextor-demonstrates-4w...