DDC114 CLK Source

I do not have a clock signal output from my microcontroller to produce the CLK for the DDC114.  Can I connect a 12MHz oscillator directly to the CLK or should I use a Crystal Oscillator Driver (SN74LVC1GX04)? 

For CLK and DCLK the spec sheet says “For best performance, generate both clocks from the same clock source”.  What performance issues do I have if I use different clock sources for CLK an DCLK?