Slight modification to 20 mhz crystal

If I modified my board and installed a 20 mhz crystal and changed all the coding to make it use this crystal what actual performance changes would I get out of it. Other than using more power faster. For instance would this increase make any difference in the speed at which my arduino could load up images to a screen. If so, would it be worth the Tine for only 4 more mhz

20% speed improvement @20 Vs @16. Worth the effort? Could be depending on the application. But in most cases the program algorithms and functions one uses can have a bigger impact then the clock speed being used. For instance if one is using floats in their sketch a lot of speed improvement could be had converting to integer math. Using direct port I/O Vs digitalRead/Write function can have a big change in speed performance. I suspect the method and protocol used to write to your display is the biggest factor in your overall performance. There are 'smart' displays that work at a higher level protocol that off loads a lot of performance demands from your arduino and place it on the displays internal micro and it's firmware implementation.