To further your point, you can get faster access directly via RDMA on an Infiniband network than the SATA bus can push data. The fastest SATA busses are around

To further your point, you can get faster access directly via RDMA on an Infiniband network than the SATA bus can push data. The fastest SATA busses are around 16gbps I believe and you can get HDR IB switches that clock 50gbps today. With the direction things are moving, "the data center as a computer" is absolutely the right approach.