I wish I had an answer for you on underclocking. Have you tried running the faster one off of BFGminer yet? You mentioned a speedup with CGminer on your 550, I'm curious if it will run slower and cooler and if there is as big a difference in speed on the 700.
Very odd. First time ever that on default clocks that if my software runs faster people are looking for ways to slow it down. Let it be known that BFL never informed us of any messaging protocol to over or underclock the devices, so I can't see how we could even implement such a feature. If it runs slower at the same clocks that implies a software limitation.
You would have to ask Nasser about that, I know he talked about it.
Nasser
was on my skype list and I emailed him a few times and got the latest and last set of protocols, and last we spoke we discussed a way of rolling work on the device. There was never any mention of clocking commands, and the nroll-time on the device never eventuated, though this was actually months ago now. Sorry but as far as I can see all development stopped a long time ago on the mofarcher.
Since we never got a working version of CGminer, I only have second hand information that it seems to do a better job communicating with the Monarch compared to BFGminer, resulting in several people talking about speed increases. The 1.4.2 firmware has the capability to accept underclocking commands and I helped test it. Adjustments could be made to both voltage and frequency that would work until the unit had power cycled on it. I know from experiance that above 530 watts at the wall that heat becomes a major issue, so it seems that your programs capability of making them run faster is a dual edged sword.