@custom-mac: On 10.9.1, my CPU seems to be locked at 3.46GHz, so you're not alone with that (see attachments).
I think you need to revise your SMBIOS choices. Not sure but your setup lucks any kind on CPU power management (may be nullcpu kext lurking around in S/L/E). Anyway, I have both min and max states working fine, just no turbo states. From what Rehabman explained, iMac profile does not use intermediate states, only min/max/few turbo states. With iMac 14,1 at least I have CPU power management some what operational.
Here is ssdtPRGen.sh code sample:
function _initHaswellSetup()
{
case $boardID in
Mac-031B6874CF7F642A)
gSystemType=1
gMacModelIdentifier="iMac14,1"
gACST_CPU0=13 # C1, C2, C3, C6
gACST_CPU1=7 # C1, C2 and C3
;;
compared it to:
Mac-7DF21CB3ED6977E5)
gSystemType=2
gMacModelIdentifier="MacBookAir6,2"
gACST_CPU0=253 # C1, C3, C6, C7, C8, C9 and C10
gACST_CPU1=31 # C1, C2, C3, C6 and C7
;;