Cocos2d-x generally slow on Android. Why?

cocos2d-x C++
#1

I built a test/empty project (Hello World!) for iOS and Android. In iOS devices, it runs smoothly with 60 FPS. However I can’t achieve a consistent 60 FPS in Android devices. I get 20-60 FPS with Android devices.
I tested with Galaxy Note, Nexus 7, and a lower-end Samsung device (Android 2.3.6).

Any ideas why? And and some fixes? Thanks!

Cocos2d-x and poor updates!
#2

This could be the sleep setting.

Check this link http://www.cocos2d-x.org/boards/6/topics/14871?r=19010#message-19010

Short story:-
Cocos2dxRenderer.java, function onDrawFrame
The Thread.Sleep probably has a * 2, I removed it and get a more stable frame rate.