Perhaps not compared to memory, but that gap continues to look smaller and smaller.
The new PCIe/NVME drive's bandwidth looks to be within 1(-ish) order of magnitude of ddr3. Apple is claiming ~3GB/s read ~2GB write and iirc 1600mhz ddr3 is somewhere around 20GB/s rw. I don't know what the latency numbers are, but I know the NVME/PCIe bus is a dramatic improvement -- not saying it will be measured in nanoseconds, however.
I have some fusion ioDrives at work that have about 3GB/s r 2.5 w with ~30 microsecond latency over the PCIe bus. Exciting times we live in for io :)
