Here are few things you can do:
1) Increase the RAM and CPU power on the ADA console
2) Delete the inactive, system generated applications from the database:
- Open a command prompt with admin priviledges
- mysql super
- delete from applications where inactive=1 and UserModified='N';
3) Modify you subnets configuration to encompass a smaller subset of your network (only the most important applications/servers). This will lower the amount of data coming into the console and increase the performance. If ADA is able to process the datafiles quicker (within 5 minutes), it will ensure that the APM connector works properly.
The bottom line is that ADA is being sent too much data. To ensure performance over the long term, you will need to decrease the total amount OR split the data between 2 or more ADA environments.