Thought experiment: HDD with flash read-cache?

[GullLars]

Then you could call all HDDs hybird platter/RAM since they use 8-64MB RAM cache...
One other point against calling this type of HDD with flash read-cache is ALL data is stored on spinning platters, on a hybrid drive you would have some data stored on flash that's not stored on HDD. That's at least what i think of as a requirement for naming it hybrid.