Keep in mind that Turbo Boost is used only by the operating system and the running applications, so those are the ones that determine when to use this feature, in this particular case I would suggest making sure that the Enhance Intel SpeedStep® Technology is disabled on the BIOS of the motherboard, since this feature will force the processor to run slower in order to save power consumption, the option on the BIOS is usually called “EIST” but if you have a third party motherboard and you cannot find the option , please contact the motherboard manufacturer for further assistance.
Also install the latest BIOS version for your motherboard if you have not done that yet.
What are you using to monitor the CPU frequency? Some programs do not update that data fast enough, or just read it once and display it. Turbo boost must also be enabled in the BIOS, you should check that it is. You should see your CPU run at 3.6GHz at least some of the time depending upon what is creating the load, but you also need an appropriate program to monitor the CPU's frequency.