What did you set the fan speed at 40? The freq at 500 with fan at 40-50 works well.
The fan rpms dropped as the evening got cooler, they hung around 5000rpm all night. The unit ran for over 9 hours and averaged ~3.4+ TH/s for the run. I shut it off for the day because it will be too warm in my house when I get home if I left it running.
I am impressed with how quiet the stock fan is compared to the stock fan on the S5, so if it gets even quieter from here that will be a bonus. Also on the comparing to S5 front, I like that for only 300 watts more I get more than double the hash. I look forward to receiving the fan and checking it with my dB meter.
Yes, I set the fan to 40 (lucky guess I guess!), but I do not know how/where to read the freq - isn't it dynamic? Do you change the fan setting with the Sanyo ace?