We have an application that has some interesting memory usage issues. When it first opens, the program uses aroun 50-60MB of memory. This stays consistent on 32-bit machines. On 64-bit machines, however, re-activating the form in any way (clicking, dragging, alt-tabbing, etc.) adds around another 50MB to it’s memory usage. It repeats this process several times before resetting back to around 45MB, at which point the cycle begins again.
I’ve done some research and a lot of people have said that VB in general has pretty poor garbage collection, which could be affecting the software in some way. However, I’ve yet to find a solution. There are no events fired when the application is activated (as shown by 32-bit usage) – the applications is merely sitting awaiting the user’s actions.
At load, the system pulls some data into a tree view, but that’s the only external connection, and it only re-fires the routine when the user makes a change to something and saves the change.
Has anyone else experienced anything this strange, and if so, does anyone know of what might fix it? It seems strange that it only occurs under x64 systems.
One of the best ways to start looking for what causes the leak is with a profiling tool.
http://www.jetbrains.com/profiler/
These guys have a 10 day free trial which is normally enough to figure out the area of the code that is causing your problems.