I was under the understanding that in these things there is usually a volume/yield consideration.
The manufacturing process turns out chips of varying quality, if your tablet is going to be rated at 1.6ghz then there is a lower yield than say at 1.3ghz as the variation in the process may make the chips unstable at higher speed. Therefore although it may be possible to over clock and get away with it, it may be that the Nexus 7 chips are from the stock of chips that weren't rated to go higher for some reason.
I may have it arse about tit but this is how I always understood it, chips rated higher are rarer and therefore more expensive.
Edited by chrisbarker, 27 July 2012 - 11:14 AM.
CURRENT DEVICES -
Google Nexus 4 (Stock)
Barnes and Noble Nook HD+ (Carbon Rom)
DEVICE HISTORY -
Phones (Including SmartPhones) :
Bosch 509e, Nokia 402, Nokia 702, Nokia 3210, Nokia 3310, Siemens C35i, Nokia 3330, Samsung A300, Panasonic GD75, Sony Ericsson T68i, Sony Ericsson T610, Sony Ericsson P900, Nokia 7600, Nokia N-Gage, Samsung E720, Nokia 6230, O2 XDA Mini S (HTC Wizard), T-Mobile MDA Vario 2, O2 XDA Orbit 2, LG Renoir, HTC Diamond, Blackberry 8800, HTC HD2, Sony Xperia Play, ZTE Blade, Nexus S (AMOLED), Nokia Lumia N800, Nokia Lumia 520
Casio Cassiopeia E-125, Psion Series 5, HP IPaq 2400 & HP IPaq 3715, Nokia N770 Internet Tablet, ASUS EEE PC 701, Samsung NC10, Advent Vega, Nook Color, Nexus 7,