...I noticed in /proc/cpuinfo the following:
... power management: ts ttp tm 100mhzsteps hwpstate 
Just because it is listed in the CPU info doesn't mean that CPU frequency scaling/powerstates are enabled. Check some of the files in the sysfs, i.e. around /sys/devices/system/cpu/cpuN/cpufreq/*. It kinda depends on your distro and how (if enabled) it is handling cpu power management: you can usually get the desired effect by uninstalling something that is tickling those files on your behalf (one such package is acpid or apmd, but note that removing these, especially acpid, may have undesirable side-effects a la ACPI events no longer triggering events, like special buttons on the case).
If you really, really want to make sure you're getting the firehose, you can always download the kernel, use the config of the one you're currently running as a basis, and de-configure power management in the kernel itself. If you want to go down this path (it's not so bad, but you will get your hands dirty) let us know and we can walk you through it