Look at the first page of cpu-z and verify the CPU version.
The Clawhammer C0 version, the oldest of A64 mobile until mid-2003, supports ONLY 1T. One can tweak it with A64 Tweaker or SisTool, but most of the time, it would give quite nasty effects. The newer (revisoned) Clawhammer (CG) offers the possibility to use the 2T Command Rate (sometimes called CPC -Command Pipe Cycle?) in order to support higher (fast) ram - slowing down to make it more stable :-) (it does hold true for driving, is it not?)
The control of 2T is mostly in BIOS when it is available. Many users use a tweaker to change this when trying to push, let say a 166MHZ ram to 200MHZ ram, per example, or on some desktop, use 2T to "brake" fast ram, timing relaxing (both foot on brakes and gas pedal - as they say).