We recently migrated from Project Server 2010 to Project Server 2013.
We have two performance problems that plague us. They come and go, seemingly randomly. Efforts by inhouse SQLServer DBAs and system techs, Microsoft Premier and other MS partners to discover the bottlenecks have been futile.
1) Project Publish gets stuck in Reporting (Project Publish) step - can take up to 15 minutes. At other times, the same project will publish all its steps, including that one, in a minute. It is not always the same project. It can be one with a 20 task schedule or one with a 300 task schedule.
2) We have three SSRS reports that pull together data from SP List on Project Site (Risks, Issues), PDP data (out of box and custom fields), and the project schedule. These three reports sometimes (especially one of them) take up to 10 minutes to run. But usually, the same report for the same project will run in less than four (4) seconds.
We've run traces and checked system logs for load, blocks, etc. The SQLServer databases have been reviewed and tuned for best practices. The web/app servers and the DB server (all VMs) barely blink with the workload from our users.
There seems to be no consistent time of day when the problems occur.
The problem will occur with only one or two users on the system.