EDIT: btw can you add an option to be able to disable each chip? I just figured out how to get below 0.65w/GHs but the hashrate is dropping in/out due to some chips die/come back. I will post back the result to show others how.
Share you method. Have you lowered the voltage or limited the PSU max power? If it's either of the methods have you tried the other one?
Its involved alot of work so i spent basically all this weekend. Its not done as i need a software solution to disable some chips. I really hope Zvisha can update firmware to tune them better( downclock or disable chips with high temp)
First, i removed all the 6 tiny fans, these are like 8watt each (the loudest fans i've ever heard). Stacking all the miners with some pink foam as spacer i use Nidec 120mmx38mm fans at the back (0.8A) for a total of 9 fans for 8 SP10s. For anyone with just 1 SP10, you can get away with only 2x120 Nidec fans . These are server fans, not your consumer cooling fans. They're strong yet not as high-pitched loud.
I actually removed all the tiny fans when i collocated the SP10s with special ducting work, so i already got this step done. Since i now gonna host them in at my office closet, i use the 120mm fans
Second, my setting is :
Fan: 40% ( the minimum setting by default but i feel this does not control PSU fans as i thought, zvi, can we control the PSU fan?)
start voltage: 0.585v
Max voltage: 0.595v
Max power consumption: 700w.
All this got me: 600-640w at 920GHs-1000GHs.
BUT i'm gonna see if i can physically KILL some chips as i dont have a software option. Reason you need to do this is because some chips will get way too hot and they throttles the whole miner. Since you removed the tiny fans, some chips will get alot hotter due to not having balanced air flow. Thats ok. I actually find having chips completely disable yield a better w/GHs. Only let the coolest chips work at their best efficiency is the way to go.
I also have another idea, but i dont have time to play. I'm sure it will work even better based on my calculation:
Remove all the boards ( i dont know if we can remove the mainboard from the controller, can SP confirm this? are they soldered together? they're looked like the pins are very strong)
Get a small fish tank and dump them in mineral oils. you have to space all the motherboard tightly together with no gap. Its required for flow balancing.
Use a centrifugal drive pump, inlet and outlet from each end and a alu car radiator.
You got the idea...etc