Yes, that's what I thought, but just looking at mine with GPU-Z and it says 1980MHz when running the render test. Did I overclock a couple of weeks ago by accident and forget?!
No this is normal, the boost clock stated for both FE and AIB is mostly irrelevant. Nvidia boost will monitor power and temperature on all cards and boost as far as it can within setting Nvidia consider safe.
1850 - 2000 is normal
When Nvidia state the boost clock is 1665mhz for the FE this means they are fairly confident you can hit this clock speed in some of the worst case scenarios, in a tiny ITX case with high ambient temperature.
Same goes whatever boost the AIB's advertise, it's a minimum boost but expect more under normal conditions.
This is why the OC models are such terrible value, many don't boost higher than the non OC.