One of the major features that DataCore's SANmelody brags about is using RAM as cache (up to 30GB in 32 bit, I believe). This seems like a very obvious approach, but I never hear it mentioned with Open-E or OpenFiler? Does Open-E behave also have this feature?

I see that some posts say file I/O mode DOES use it, while block I/O doesn't. With that in mind, why would anyone use block I/O mode? It must be there for a reason?