Spanner maxes out at ~10 transaction (batches)/second in that paper. By comparison, a standard PostgresSQL installation (on littleish iron) is capable of 50k TP

Spanner maxes out at ~10 transaction (batches)/second in that paper. By comparison, a standard PostgresSQL installation (on littleish iron) is capable of 50k TPS depending on the benchmark you're running. In the Spanner design the maximum throughput is governed by the accuracy of GPS and atomic clocks and, ultimately, the speed of light. You can only make 7 round-trips per second between a data center in New York and on in Singapore unless you're willing to bore a hole through the center of the earth. Order is expensive and, more fundamentally, coordination is expensive. At the center of traditional OLTP workloads is a promise given by the system to the developers that their transactions will happen in some order. Peter Bailis and Joe Hellerstein are two prominent academics working on addressing this problem, and at the core of their research is giving up pieces of this promise.