title: How to read FPS measurments in Mac 'Instruments' (Core Animation) while debuggin Mobile Safari on iPad comparing to Chrome Dev Tools FPS reading?
body: <p>I'm using Yosemite and OSX Xcode 'Instruments' (Core Animation) to measure FPS in my iPadMini Mobile Safari browser app. However, the reading I get looks contrary to the reading you get while using 'timeline' and Chrome Dev Tools. Please see the image from 'Inststruments':</p>
  
  <p><img src="https://i.stack.imgur.com/f5oAz.png" alt="enter image description here"></p>
  
  <p>and Dev Tools Timeline:</p>
  
  <p><img src="https://i.stack.imgur.com/C4wrM.png" alt="enter image description here"></p>
  
  <p>When you don't perform any action (fire no events) in Dev Tools you get 60fps+ (see the image above) and that what I would expect. However, in Mac 'Instruments' - Core Animation - in the same state you have ~7fps and FPS rate rises as soon as you start fiddling with the application (fire some events).</p>
  
  <p>I'm confused and would appreciate any help.</p>