Quote from: RichBC on August 05, 2015, 06:20:24 PM

Quote from: Moria843 on August 05, 2015, 12:19:44 PM

Changing the frequency alone won't significantly increase the efficiency. You have to also reduce the chip voltages through the pencil mod or adding resistors (using voltage setting available with some firmware does nothing). I reduced by adding 8 resistors to each hash board of 4 S3s. I set each to the frequency that was the most efficient. The slowest hashes at 250 and the fastest at 390 Gh/s. I'm now averaging 0.62 J/Gh, which is still profitable.

I am also in the middle of some decision making on which system to go for with a key factor being efficiency. I have modified a board in my S3 with digital pots to make experimenting easier.

https://bitcointalk.org/index.php?topic=1127340.msg12040549#msg12040549

The best I have seen was at 125Mhz, 0.64V Core Voltage, giving a hash of about 254GH which is J/GH of 0.48

Rich

I could not find anywhere note that 150 & 175 freq much "Voltage" must be the core?

.680 or is it a lot?