Quote Originally Posted by phibermon View Post
It uses a ton of memory (I assume it has to be creating back-buffers for every control to use as much as it does)
I also assume something like this. But not so much due to memory requirements but based on some of its features like zooming ability which clearly simply scales up the contents of entire control.
Another problem with FMX is that unlike its first few iteration it does not natively support vector graphics rendering which means that for each control you need to have respective image. These images are stored within those styles that FMX use. And I seriously doubt that FMX has proper algorithms for optimized storing of this resources in VRAM which might be another cause for high memory usage.

Quote Originally Posted by phibermon View Post
But it's not very suitable as the GUI for a 3D game for example - that needs total control and utilisation of the hardware
If you ask me it is not very suitable as the GUI for any game or even for any more complex application for that matter. Why?
Go and make a next test example. Create a new FMX project and simply put about 100 to 200 controls on it. Compile the project and then preform quick mouse movements around your FMX application and you will se that the CPU usage will rise significantly. In fact this issue is so bad that if you have an application with complex UI mouse movement can cause application lag. To me that is unacceptable.
Remember when in another I mentioned that I'm still not sure whether to use FireMonkey for my texture creating application that I'm creating or first finish my Silver GUI library and use that for my application UI. The reason for my dilemma is the fact that even with partially done UI in FMX I'm already noticing performance issues and we are talking here about texturing application that does not have any kind of fancy graphics or animations for its UI.

To be honest I'm wondering how people can make any mobile application using Delphi ad FireMonkey which isn't lagging as hell since mobile phones have much weaker processing capabilities compared to desktop computers on which you can already notice FMX to lag as hell.