Does crystal limit processor speed?
The STMicro F205 Cortex M3 contains an internal PLL that can clock the processor all the way to 120 MHz. It can use an internal 16 MHz RC oscillator to drive the PLL or an external 4-26 MHz clock source.

So technically the processor can run up to 120 Mhz, however, that top speed depends on how your firmware programmers set up the PLL.