[dylan@Laptop ~]$ sudo modprobe speed
speedstep-centrino  speedstep-lib       speedtch
speedstep-ich       speedstep-smi       
[dylan@Laptop ~]$ sudo modprobe speedstep-centrino cpufreq_ondemand && cpufreq-set -g ondemand -u 1.5GHz -d 600MHz
FATAL: Error inserting speedstep_centrino (/lib/modules/2.6.17-beyond/kernel/arch/i386/kernel/cpu/cpufreq/speedstep-centrino.ko): Unknown symbol in module, or unknown parameter (see dmesg)
[dylan@Laptop ~]$ sudo modprobe speedstep-centrino 
[dylan@Laptop ~]$ sudo modprobe cpufreq_ondemand && cpufreq-set -g ondemand -u 1.5GHz -d 600MHz
Error setting new values. Common errors:
- Do you have proper administration rights? (super-user?)
- Is the governor you requested available and modprobed?
- Trying to set an invalid policy?
- Trying to set a specific frequency, but userspace governor is not available,
   for example because of hardware which cannot be set to a specific frequency
   or because the userspace governor isn't loaded?