I have a solution that has been running fine on FM Server for many years (about 10 years).
I updated the application to FM13 from FM11 and now I have some erratic performance. Every so often a client will just freeze up (beachball, OSX). They don't even need to be using the application. This will last for 30 seconds or more.
Is this because the server can't handle FM13? It doesn't appear to be running out of RAM and it has an SSD, mostly it's a cheap server but I can't see problems.
For testing I moved the application to a different server, a desktop machine and the same thing is happening. The network tests fine, accessing the file locally has the same issue so it shouldn't be a problem with the network.
The database filesize is huge but it is well optimised and performs very well apart from the random freezes.
The FM Client has 100% CPU utilization when it happens, but the server does not appear stressed.