Why Android's UI appear lagging compared to other mobile OS

[Dragonball Z]

I have seen significant differences between the android OS user interface and other OS user interface? Anyone knows the reasons for it?

[Memphis M]

According to research, it is found that android UI lags because it uses main thread with normal priority where as in other OS they have used real time priority for user interfaces. There are also some other reasons that are as follows:
1.Android has photo gallery application which uses frame rates of 60. Which was also consuming more battery . Latest versions of android version have this problem solved. They have decreased 60 frames per seconds to 30 frames per seconds.
2.Android phones have Nvidia’s Tegra 2 chip, which reduces the performance because this chip has low memory bandwidth.

[akkiiii]

Google’s student explained that androids design is very much complex than other OS. Main cause of this is that animation part need to be re-drawn every time. He also stated that android system was never meant for touch screen, it was made for mobiles with keypad and trackball.
So there will be re-designing in android systems. But only redesigning won’t solve the problem as the old application should be supported in new design. Developers will have to keep this in mind while making new design.