There are many timers in the machine, and in the kernel. You would need to be more specific as to which timer you want to adjust.
Although I don't know that you could reduce any of them to 64Hz, you do have several options including "Tickless Kernel" which only causes clock interrupts when needed, and also there is the "latency" timer, which affects kernel response time, and has such settings as 250, 300, 1000, and one other Hz setting which I can't recall at this moment-- I think it's 100Hz, which may make your machine slow to respond to your input, but *might* save some small amount of power. I believe the intent of the timer speeds is more so the kernel itself reacts faster or slower to certain types of events, not necessarily to save power. To save power, you may want to look into CPU frequency throttling instead..
You would need to recompile your kernel to change one of these settings (I'm pretty sure, though you *might* be able to use the /sys interface to change this too.. Not sure) after having adjusted the setting in either xconfig or menuconfig or whatever interface you use to configure your kernel source code before compiling.
@ cola -- I agree, your one-word reply is pretty useless. Please take a moment next time to give an informative reply, or none at all. Thank you.
Last edited by GrapefruiTgirl; 10-13-2009 at 08:42 PM.