I Got an AMD FX(tm)-8350 Eight-Core Processor with 4GHz frequency and up to 4,2 GHz Turbo Core speed, but I cant get the Turbo Core to work.

dmesg | grep powernow

should tell me something like:

[ 2.187170] powernow-k8: Found 1 AMD FX(tm)-8150 Eight-Core Processor (8 cpu cores) (version 2.20.00)

[ 2.187204] powernow-k8: Core Performance Boosting: on.

[ 2.187250] powernow-k8: 0 : pstate 0 (3600 MHz)

[ 2.187252] powernow-k8: 1 : pstate 1 (3300 MHz)

[ 2.187253] powernow-k8: 2 : pstate 2 (2700 MHz)

[ 2.187255] powernow-k8: 3 : pstate 3 (2100 MHz)

[ 2.187256] powernow-k8: 4 : pstate 4 (1400 MHz)

but it shows nothing. Checked if powernow-k8 is loaded via modprobe, and it is.
Turbo Core and APM are enabled in BIOS, Cool n Quit also.

cpufreq-info

tells me that

driver: acpi-cpufreq

is loaded, but maybe it should be powernow-k8 like I saw on other posts. May that be the issus why Turbo Core is not working, and if yes, how can I change the driver to powernow-k8?

I use Ubuntu 14.04 with newest Kernel.