I found the type of the PLL chip (clock generator) in a service manual I got from Dennis W. Strickland. The type of the PLL is ICS 952623 in the 171x serie. I played with the cpucool and the cpufsb but I still didn't find any setting that is reliable.
In most of the cases the LCD goes blank and the system hangs.
I tried to set the freq around 133,33 MHz (it would mean 533 Mhz FSB instead of 800). The base freqency is 200 Mhz (199,5) in 1714smi. This is multiplied by 4 and it results 800 MHz FSB.
I tried 166,6 - 133,3 - 100 - 66 and 150 Mhz settings. Some of the frequencies that didn't work:
133,27 - this was the one that worked at least 10-15 seconds after decreasing the FSB. After this the system hangs for about 10 sec periodically.
Please tell us if anyone found an exact frequency that works.
If we would find a frequency that is useable would be great. Because the FSB could be modified by the cpufsb program from windows without restarting the system. So if I wouldn't need much power (surfing or typing program code) I could safely decrease the FSB with two clicks. This seems to be the only one method to force any power saving (and hopefully less fan activity and more silent working) on this machine/processor.