as far as it looks like, iam not the only one, crunching on arm. dzone got a article from thailand, where some guys connected 22 cubieboards, runinning apache spark, for in-memory-computation.
but ive seen the bottleneck of a 100 mbits network connector on cubieboard pretty much earlier. so ive decided to buy the cubietruck, which includes a 1 gbits adapter, which brings theoretically 128 mbyte/s a sata drive for saturation.
i calculated 8 cubieboards in a 1 he server rack as maximum amount of boards and hard discs last year. the price is then something like 1600-2000 € for the hardware. for that price tag, the memory of 16 gb ram and 16 tb of hdd is not that much, but the theroretical bandwith between the nodes ( within the cluster ) is something like 8 gbits
the picture above shows the former choosed boards from hardkernel, called odroid, but the price for that board is above the budget, so i sized it down to a dual-core, from the quad-core.