Task Manager Shows Incorrect CPU Frequency

I put a slight overclock on my FX 6300 by adjusting the multiplier in AMD Overdrive (17.5 to 19). The frequency in Overdrive shows as 3809 Mhz, also 3809 Mhz in CPU-Z. Task Manager (Windows 8.1 Pro, 64 Bit), Shows a constant 3.43 Ghz.

When I unclick the Red Button in Overdrive (turning off the overclock), my cpu frequency will drop down to a lower value (say 1400 Mhz) and then bounce around to higher values depending on load, and spread the load around the 6 cores.

In this case Task Manager does show the CPU frequency fluctuating around also (2.31 Ghz, 2.52 Ghz, 2.73 Ghz, etc.) Also in Task Manager it shows the Maximum Speed as 3.5 Ghz.

Has anyone else experienced Task Manager showing apparently incorrect CPU frequency?