one thing I noticed is that if the fan is set too low manually on the mini batch 4 the machine will cut speed back accordingly. So if the controller sets the fan to say 4500rpm and you drop it too low the speed will reduce. The batch 4 mini's need a fan simulator and other hw mod to fan to run batch 1 firmware unless you don't mind the fan running 100%
What do you mean "cut speed back accordingly"? Are you saying the frequency and hashrate drops?
Otherwise, I would not expect a "fan simulator" to not act any different than a regular fan in the condition you have described.
Another point on the "batch 4 minis" is that I believe their availability is only mainland china?
-j
If cgminer wants the fan to run at a certain rpm and you lower it below what it is expecting the hashrate will drop and eventually goto 0. The batch 4 mini I have been playing with runs in fault mode because of the coding for the temp. When I manually lower the fan to say 5000 rpm from the 5880 it sets due to the fault the hashrate will drop until I bring the fan back to the 5880 rpm. Personally fan checking should be disabled to get around any issues with a fan simulator or the fan itself. I tried bypassing the checking but failed on my first attempt cgminer wouldn't even load. I screwed my board now it wont detect the fan rpm no matter what the circuit is good so I figure playing with it killed it on the processor but I did try a v9 controller and same issue with fan runs at full on the batch 4