Low cpu frequency after oc

[Opits]

I decided to increase frequecy of my x4 860k cpu from 3.7 to 4.0, i first increased to 3.8 then 3.9 and 4.0, tested every frequency, it was stable, no chrases, but i noticed that cpu on 100% is running at lower frequency, i overclocked to 4.0, cpu is running on 3.5... help pls

Max temp was 66 c, overclocked in bios, using prime 95 to stress the cpu, open hardware monitor to monitor temps and frequency, cpuz for cpu stats

 

You can see the problem on the picture

 

 

[Windows7ge]

Does your BIOS have an option to run the CPU at max clock speed 100% of the time? That would tell you if the system is really reaching the specified clock-speed.

 

Also if that works but once you load up Prime95 it down-clocks again that means you're thermal throttling but I don't know the TJ-MAX for AMD Athlon CPUs so I can't say that's the issue. I do know though that my old AM3 Phenom II B55 had a max recommended temp of 55°C and you're pushing 66°C on an even older chip so that could be the issue.