Performance Analysis of Ethereum Clients Geth and Parity

It would be easiest to write a script to do this. web3.py provides an easy wait_for_tx function that would allow you to do this in very few lines of code.

Ifnderstand your goal correctly, though, the results will be underwhelming. The performance bottleneck will be the Ethereum network, not a specific client. Each client will be able to process the transaction in under a second, but both will have to wait until the transaction is included in the network before sending the following transactions.