>Broadly, the notional value of storage technology like Optane is that it offers a drop-in improvement in storage performance without requiring any software mod

>Broadly, the notional value of storage technology like Optane is that it offers a drop-in improvement in storage performance without requiring any software modification, albeit at a significant cost premium. I don't think so at all. The value of Optane was that it was dramatically different, offering byte-addressable storage with latency of hundreds of nanoseconds. Getting the most out of this requires radically redesigning how modern systems store data, including ditching the idea of block storage. Optane was the fastest traditional SSD on the market by a pretty wide margin, but that's not all it could have been. >They use the storage so well that the gains by putting something in the middle will be marginal or non-existent, and certainly not worth the extra cost. I don't agree with this either. How do you propose to get latency down to match Optane using ordinary SSDs? It doesn't matter how much hardware you throw at the problem; parallelism cannot reduce latency. You need another storage system to hit those targets. Maybe that can be a more traditional DRAM cache with battery backup, but that's only adequate in bursty workloads. Putting "something in the middle" isn't worth it if the rest of the architecture stays the same. But it could bring about tremendous speedups if the new capabilities were used.