Unfortuantely there is (to my knowledge) no boundry for the number of projects a Project Server 2013 can host. The only mentioned limits are:
- End of project time: Date: 12/31/2149
- Deliverables per project plan: 1,500 deliverables
- Number of fields in a view: 256 (A user cannot have more than 256 fields added to a view that they have defined in Project Web App.)
- Number of clauses in a filter for a view: 50 (A user cannot add a filter to a view that has more than 50 clauses in it.)
Reference: Software boundaries and limits for SharePoint 2013 (Project Server)
But having as many as 140'000 project seems to be too many. Ordinary List view thresholds are defaulted to 5'000 for users and 20'000 for admins.
I would advice you to monitor the SQL Server performance. Do you have long running transactions which causes other queries to halt? How do the SQL Server memory and CPU doing? Are continuously above 90% on memory, a test would be to add more memory to the SQL Server. Is the LOG disk almost full? is another cause of bad performance which I've encountered more than once.
Microsoft recommend in the article Scaled-up and scaled-out topologies in Project Server 2013 two different approaches:
To provide for more data load
- To provide for more data load, add capacity to the database server by increasing the capacity of that single server.
- Separate the Project Database from the SharePoint Databases by moving the Project database onto its own dedicated database server.
Unfortunately, you can't implement SQL replication...
Project Server 2013 does not support scaling out the Database
component through SQL replication. While it is possible to perform SQL
mirroring on a Project SQL Server for the purposes of backing up data,
Project Server 2013 is unable to take advantage of SQL replication to
reduce read loads on the SQL Server.
At the very end Microsoft recommends the following:
How to spend money on scaling up and out:
As a general rule, in the early stages of scaling your Project Server
deployment, you will want to invest primarily in purchasing additional
memory. Most often, the subsequent areas you would want to invest in
are disk spindles, and then network resources.
But I would start with monitoring the SQL Server. Usually you find your performance issue there.