Barely faster than NVMe SSDs when fully saturated. At low queue depths and in mixed workloads (especially when overwriting data) Optane absolutely destroys the competition. This is a database dream drive. Only problem is the low capacities right now.
> Barely faster than NVMe SSDs when fully saturated.
The Optane products released thus far are all literally NVMe SSDs, which is why their best-case latency isn't much better than that of flash-based NVMe SSDs. They still have PCIe and NVMe protocol overhead to deal with, which the 3D XPoint DIMMs won't have.
The unimpressive peak throughput of the current Optane SSDs is largely a consequence of the Optane SSD controller having a fairly low channel count. A single 3D XPoint DIMM will probably have substantially higher throughput than a current Optane SSD.
I also wonder if the current products are bottlenecked by the controller and whether DIMMs will see vastly superior performance. Guess we'll have to wait and see.
> I also wonder if the current products are bottlenecked by the controller
There's no question that they are. NVMe drive prototypes that use DRAM as their backing memory instead of flash or some other persistent memory have about the same overall latency as Optane SSDs.
With NVMe, the storage industry is in a much better position to take advantage of 3D XPoint than if we were all still using SATA or SAS, but it's still on a peripheral bus not a memory bus.
