Thanks Dezsoe, then it seems my bet was correct about what could cause the issue.
BTW, Gerry, you wrote that the peak memory usage of the UCCNC is around 10GB when you loading your large 100MB file.
Maybe you can upload that file somewhere to let me download and check?
I'm asking this, because 10GB sounds a lot. When I'm loading a 200MB file the peak memory usage is around 3.5GB which falls back to about 2.5GB when all garbage is collected by the .NET garbage collector which happens when the file is fully loaded and no more needed stuff are all disposed and goes to garbage collector and then deleted.
So, I can think of 2 things, that your code contains lots of vertices which is only possible that it contains much more than my code if it contains lots of arcs, because my code contains only G0 and G1.
Or the Windows 10. task manager is less precise than Windows 7. in estimating memory usage of applications.
The thing is that the UCCNC using managed and also unmanaged memory, one reason for that it is mixed language application, so however Windows 7. mostly still estimates the used memory close enough, but maybe the Windows 10. algorithm for this is worse. Sometimes Windows 7. is also incorrect about it, I know because I verified the memory usage a few times along the development, but usuallythe Win 7. task manager is really close to the truth.
So, I'm not sure which one is the case, so if you could share that file then I will try to load it on my Win 7. x64 computer to see how much memory it peaks on this PC.