5000 per second with --innodb_flush_log_at_trx_commit=0, which only writes the log to disk once per second.
The MySQL documentation claims that this configuration does crash-recovery correctly, though you may lose the last second's worth of transactions.
Robert, did you test MySQL with a parallel load? To give it the best chance at maximizing tps, it will need to be able to combine multiple pending transactions in a single write. Also, can you tell if it's updating it's b-trees? (if not, it may not be able to sustain these rates)