CPU frequency won't go beyond 800MHz on my Dell XPS 13 with ivybridge

I cannot go beyond 800MHz on my Dell XPS 13 Ivybridge CPU.

Even if issue sudo cpupower frequency-set -g performance I still get 800MHz. Then I tried

...no luck. My laptop is slow especially when running on battery. I saw that there was an open bughere which seems to be similar to my experience but it was closed for not enough info. Can someone help me please?

EDIT:

I booted with the intel_pstate=disable option and now I can set frequencies and governors. However my laptop is still slow and unresponsive even in performance mode, so there's something else giving problems.