Configuration of the MX64's clock frequency, and clock multiplier is done from the "Chipset Features Setup" BIOS menu. Also, on the motherboard itself are two jumpers (JP23, and JP29) that permit the setting of the reference frequency that may be ranged from in the BIOS.
Available choices include: automatic adjustment by the system, 66Mhz to 83Mhz, 100Mhz to 124Mhz, and 133Mhz to 150Mhz. Also within the BIOS, it is possible to set the operating frequency of the memory bus equal to that of the system bus, with the option of adding or subtracting 33Mhz from that value. No ability to adjust the processor's core voltage is provided.
Available clock frequencies, include: 66 - 75 - 83 - 100 - 105 - 110 - 112 - 115 - 120 - 124 - 133 - 140, and 150MHz. Clock multiplier are available from 1.5X to 8X in steps of .5X.