A $2k computer can execute about 8k transactions per second. This is 80x more than one of the largest US bank's 1970's traffic - it approximates the total US 1970's financial transaction volume. Very modest modern computers can easily solve yesterday's problems.
@article{arxiv.cs/0701161,
title = {Thousands of DebitCredit Transactions-Per-Second: Easy and Inexpensive},
author = {Jim Gray and Charles Levine},
journal= {arXiv preprint arXiv:cs/0701161},
year = {2007}
}