I think that tethering the storage to the compute nodes would work better.. 16-32GB on the same board with the arm chip, in clusters per nU, per rack ... Reducing the bottlenecks from data storage to the processor. In this kind of scenario widely distributed databases could be a much better fit in ARM than in x86 based servers.
Imagine how fast Cassandra or something similar could run if your filtering nodes ran with the data, and much more widely distributed than typical... it could literally be a night and day difference in the amount of data that can be processed in a rack.
Imagine how fast Cassandra or something similar could run if your filtering nodes ran with the data, and much more widely distributed than typical... it could literally be a night and day difference in the amount of data that can be processed in a rack.