068f2f15_Improving_Drawing_Performance__improving_drawing_performance_Tip
[Action] The Core Animation instrument can help you spot drawing performance problems in your app. In particular: Flash Updated Regions makes it easy to see what parts of your view are actually being updated. Color Misaligned Images helps you see images that are aligned poorly, which results in both fuzzy images and poor performance. For more information, see Measuring Graphics Performance in Your iOS Device in Instruments User Guide. [Tip] 
Use Instruments to debug your performance
Improving Drawing Performance