Add troubleshooting section

describing how to change intel_pstate driver to acpi-cpufreq

README.md

@@ -121,6 +121,23 @@ If daemon has been installed, live stats of CPU/system load monitoring and optim
 
 `auto-cpufreq --stats`
 
+## Troubleshooting
+
+**Q:** If after installing auto-cpufreq you're (still) experiencing:
+* high CPU temperatures
+* CPU is not scaling to minimum/maximum frequencies
+* suboptimal CPU peformance
+
+**A:** If you're using `intel_pstate` CPU management driver consider changing it to: `acpi-cpufreq`.
+
+This can be done by editting `/etc/default/grub` file and appending `intel_pstate=disable` to `GRUB_CMDLINE_LINUX_DEFAULT` line, followed by `sudo update-grub`
+
+Example line change:
+
+```
+GRUB_CMDLINE_LINUX_DEFAULT="quiet splash intel_pstate=disable"
+```
+
 ## Discussion:
 
 * Blogpost: [auto-cpufreq - Automatic CPU speed & power optimizer for Linux](http://foolcontrol.org/?p=3124)