Two things: Where's the benchmark compared to memcached? Several years ago there was memcachedb, which could flush stuff to disk. While this operation was exp

Two things: Where's the benchmark compared to memcached? Several years ago there was memcachedb, which could flush stuff to disk. While this operation was expensive, it was also useful, because you could restart instances without being overwhelmed by missing keys (data). For the latter: your application quickly grinds to a halt if you need to build your cache from ground up after some kind of crash. This is a deal-breaker for many.