Network / Disk IO a bigger factor in DB perf

Unless you are doing heavy calculations in the DB TPS and Throughput are far more likely to be bottlenecked by your network and disk speed.

If you want something really, really fast and massively scaeable for certain classes of problem an in memory MYSQL CLUSTER plus a native threaded c++ NDB api client (eg. mod_ndb) easily beats everything else out including the commercial offerings for performance.