Why setting hardwareaccelerated to false make things faster?

Question

I have an application running on tablet devices with two panes, for the left one I have a simple animation on replacing a fragment:

private void loadLeftFragment(Fragment fragment, boolean isAnimated) {
        FragmentTransaction fragmentTransaction = getSupportFragmentManager().beginTransaction();

        if (isAnimated) {
            fragmentTransaction.setCustomAnimations(android.R.anim.slide_in_left,
                    android.R.anim.slide_out_right);
        }

        fragmentTransaction.addToBackStack(null);
        fragmentTransaction.replace(R.id.left_frame, fragment).commit();
    }

Please notice the animation peace of code. It runs perfectly smooth on Nexus 7, but on Galaxy Tab 2 it is not. So I experimented with android:hardwareAccelerated="true/false" tag in AndroidManifest.xml. And what I got is that when the value is set to false the animation on Galaxy Tab 2 is such as on Nexus 7, i.e. smooth and good looking. I didn't expect such a behavior assuming it should be vice versa - setting the hardwareAccelerated value to true makes things 'smoother'. But it happens if I set it to true I see lags, when false it is just nice! What I'm missing here? Thank you.

Answer 1

Well it all depends on the memory usage. What happens when you turn on hardware acceleration is, app’s animations and UI rendering happens with the GPU and that causes the system to take a hit to memory usage. Loading up the OpenGL drivers for each process takes memory usage of roughly 2MB, and boosts it to 8MB. On devices with limited RAM, this can be a real issue. When more RAM is eaten up, the system will necessarily have to close more background tasks to save memory.

So this option must be used cleverly and depending on the target devices.