A post from “max_power” points out that GtkPerf has a Hildonized version that runs in Maemo.

The GtkPerf site says:

GtkPerf is an application designed to test GTK+ performance. The point is to create common testing platform to run predefined GTK+ widgets (opening comboboxes, toggling buttons, scrolling text yms.) and this way define the speed of device/platform.

The site says the program is helpful in answering questions such as

• How fast is my hardware/software platform compared to others?
• How fast/slow GTK+ is with different themes?
• Is there any notably slow widgets when using my GTK+ theme(engine)?

It adds “There exist other performance tools but none to measure GTK+ UI speed.”