Odd CPU frequencies

I have a i5 3570k paired with a MSI Z77A-G41. I have my cpu overclocked to ~4.0Ghz in the bios with a combination of increased multiplier and FSB. DRAM set to auto and Link. When i start windows and open up CPU-Z it reads the correct overclock that i set in the bios. However, when i check windows (right click my computer and go to properties), it shows 3.8Ghz. Lastly, whenever I open RealTemp my CPU frequency changes to ~ 3.6GHZ. I reopen CPU-Z and it shows ~3.6Ghz as well. I notice the CPU multiplier has lowered itself, from 38 to 34! All power savings settings in bios are disabled (intel step, C1E, etc), and the power options in control panel are set to high performance.

Anyone able to give me some insight as to why this is happening?