Timothy Fitz Says: March 8th, 2011 at 6:38 pm The iPhone 3GS almost always ends up being the fastest of the iPhones. While the iPhone 4 has a faster CPU, they both have the same GPU (PowerVR SGX 535). While the iPhone 4 has twice the ram (which is fully addressable by the GPU), and could have a faster CPU clockspeed (I couldn’t find reliable sources), at the end of the day the iPhone 4 needs 4 times the fill rate to meet the increased resolution of the retina display, and it doesn’t have even close to 4x the fill rate of the 3GS.
http://dbaron.org/log/20100309-faster-timeouts
However the postMessage trick is near realtime:
Which means the FPS with setInterval is actually measuring how long it takes setInterval to fire, not how long it's taking to draw under the different methods.