Serial buffer or faster processing?

Thank you, this can run much faster I guess.

However, I have a standard EOP which is ":" but not a single SOP. The starting character will be an "L" if I have to drive leds but could be A,B,C,D.... etc if the software is driving various 7 segments displays (6 digits). I could modify this :

if(inChar == SOP)

in this :

if((inChar == 'L') || (inChar == 'A') || inChar == 'B'))

Do you think this could affect the speed significantly? The problem is I have no chance If I want to read every different information.