We have two performance monitoring tools in LUCY:
LUCY is designed to work with over 100 K parallel recipients on one instance. This will require a hardware with sufficient RAM & CPU. If you are not sure if your hardware meets the campaign requirements you can run the build in test module. It allows you to run a performance test in order to verify if your hardware can handle the amount of recipients. It will also check the Campaign Settings.
Once the test has finished, you can see the detailed report which will tell you, how many recipients your sever is able to handle within reasonable time frames.
Note: A test can run for more than 20 minutes - so be patient and don't use the LUCY server in this time period.