Frame rate drops while using set setDesignResolutionSize

Why does the frame rate drops when I use the following code in ipad2 simulator.
auto screenSize=glview->getFrameSize();
if(screenSize.width==1024||screenSize.height==1024){
glview->setDesignResolutionSize(768,1024,ResolutionPolicy::NO_BORDER);
}

I wouldn’t worry about frame rates in the simulator - it’s notoriously bad.

Before I started testing on a device I used to see all sorts of strange frame rate drops that just don’t happen on a device.

I now develop initially for Mac - which makes it much easier to test different resolutions too - then test on devices once I’m happy with it.

would like to thank you for your reply, I Haven’t tested in the device. If its the case like what u said for the simulator than its not the matter to worry much about. But It would be better if the issue is solved for the simulator by the cocos2dx team.

It’s apple, rather than the cocos2d-x team that would have to solve it, I think!