Does the board have a rectangular white sticker on it that says something like
AMSXXXX
WO#DMXXXX-XXXX
REV:2.1
Mine has this sticker and is working with the 1.0V fw -> around 30GH i.e. 2-3GH and 30W less, and very low HW
bfgminer version 3.8.1 - Started: [2014-03-31 14:33:42] - [ 0 days 00:19:15]
[M]anage devices [P]ool management [S]ettings [D]isplay options [H]elp [Q]uit
Connected to uk1.ghash.io diff 32 with stratum as user 2GOOD.chili
Block: ...bb0612d3 #297466 Diff:6.98G (49.96Ph/s) Started: [13:42:44]
ST:9 F:0 NB:4 AS:0 BW:[ 43/ 28 B/s] E:197.04 I:89.11uBTC/hr BS:9.36k
1 55.0C | 31.58/30.70/30.67Gh/s | A:247 R:0+0(none) HW:3/.04%
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BFL 0: 55.0C | 30.67/30.67/30.68Gh/s | A:249 R:0+0(none) HW:3/.04%
And temperature is lower too, it used to be around 68-70C with the 1.1V fw