Probably power management in action, try to load all cores with an app / software such as prime95 and you should see the max frequency showing up.
Also for the most accurate real-time frequency you should use CPUz
Sorry didn't put the right image link for CPUz, its been updated. i'll give it a try but i think it stays on 0.80
EDIT: just ran p95 still stays at 0.80 on the task manager... the volts go up though and aren't staying at 0.000 like in the picture (they go to the volts i've set in the bios)