Not All Caching is Created Equal according to Victoria. She also claims Fusion IO is always superior in her blog post at fusionio.com "Fusion's ioTurbine application level caching software is superior to any other solution because the caching decision is made in the guest OS, " Accept that means the Guest OS burns CPU cycles, and the application has to be caching aware which you can't always guarantee that it is. There is a very limited set of cases where Fusion IO Turbine is a net win, but for the most part in the cloud, virtualized, it is not. Which is why FusionIO is this weeks idiot in the cloud.