# iPhone 3GS - can't ever seem to hold 60fps with CADisplayLink

So I've switched from NSTimer to CADisplayLink and I'm still seeing unexpected variation in my frame counter - it fluctuates between 59-60fps, even when I'm not rendering much.

Has anyone else seen this? Is this an expected variation in iOS? Or should I look more closely at my game loop?

From my experience this is normal behavior. The measured time can change slightly and if 59.99 FPS are calculated and you output that with just 2 digits, it's going to show 59.

Don't worry about fluctuations of one frame.

• Ok - I was outputting XX.XX digits but it flickers too quick for me to see, and I didn't bother tracking min/max value. If other people see this then I'm happy. – Justicle Feb 22 '11 at 23:05