His new firmware for the board didnt work so well for me, the old one is faster at even lower frequencies, but i still have to debug it a little further...
Can you post any details? The frequency formula in the original firmware was incorrect, so you had to pick frequencies without any clear understanding how frequency relates to the hashrate. With my firmware, speeds 1650-1717 yield maximum performance, while lower speeds (down to 500MHz) also work well and in a predictable fashion so that the actual hashrate matches with the speed you specify, i.e. speed 500 -> 500MH per chip and so on. Here's a screenshot:
http://s019.radikal.ru/i601/1402/ca/70cccdc0e4bc.pngHere's an example command line:
./bfgminer -o stratum+tcp://stratum.mining.eligius.st:3334 -u -p --klondike-options 1718:70
substitute your pool credentials, username and password where appropriate.