I am working for an insurance company with about 180 employees. About half of these employees register something in their Claims system (sales, consulting services, claims handling etc.). The core system is written in Cobol and runs on a mainframe. Recently they bought a new mainframe for 100.000$ because they said that their old one ran on 100% constantly. After they got the new mainframe, I spoke to an employee working in the statistics department, who said that they run one to two statistics queries overnight on the mainframe, so as to not interfere with normal work on the server.
My question is: How does the performance of a mainframe compare to desktop computers. I am quite sure that I could set up a 400 dollar PC with a database and have that handle 90 employees that are writing names and addresses of customers and searching through a databaes that cannot be that big. With a bit of replication and stuff I believe I could achieve excellent performance. What am I missing here? Are mainframes always like this or is this a sign of a poorly implemented CRM system?