I thought GPU Clock Speed is that the higher the MHz, the better performance you get, but when looking at leaked previews of the 1060, it says it went up as high as 1900 MHz while the RX 480 was at 1350 MHz: http://www.3dmark.com/compare/fs/9202637/fs/9188962#

But in terms of the leaked real time FPS, it doesn't look like the 1060 is beating the RX 480 even though the clock speed is almost 50% more. So what actually determines the speed or does it vary with different cards?

These are just leaks, so I know some data are probably false, but just curious how Clock speed works.