Check out our video on how to manually tune your S19 with our Firmware:
The aftermarket firmware we are distributing for the S19 allows for manual chip tuning, which can both help to boost hash rate, but also may increase efficiency. The firmware comes with a series of presets which work well, but it also allows you to tweak each individual chip on each hash board by adjusting the voltage, as well as the MHz. Manually tuning is beneficial because each machine is different, and auto tuning function is still being fine-tuned by the development team.
Each chip takes a certain voltage and turning up the voltage (overclocking) will increase the hash rate. Likewise, if you decrease the voltage (underclocking) you may be able to attain higher levels of efficiency, though it will decease hash rate. The trick is finding the sweet spot where the chips are not receiving too much voltage, or too little voltage. You also have to keep in mind the limits of your power supply. If your power supply is modded, you will be able to increase power and reach substantially higher hash rates. A stock APW12 is rated for 3.6kW and we have seen them handle just under 4kW stably. Increasing chip voltage, will also increase power consumption, so it is important for you to monitor increases in power consumption as you increase the voltage.
The other variable you can adjust is level of MHz, which is the size of the electrical wave passing through the chips. Adjusting the MHz up or down will impact how your chips perform. If you bump up the voltage, and the chips are underperforming, you should initially bump up the MHz to see if you can them performing optimally. MHz will not increase power consumption but is another way to try and optimize the way your chips interact with the voltage that you set it to.
The firmware for the S19 gives you a visualization of how each chip is performing. The interface shows each chips hash rate in GH/s, as well as temperature, and frequency.
The chips will be colored black if performing optimally, yellow is suboptimal, and red if substantially underperforming. The goal of manually tuning is to get all of your chips performing optimally at your desired power consumption. If you bump the voltage up too high, the chips will turn red, and the board will shut off. This will not damage your board as long as you adjust the settings to bring down the voltage.
As you begin tuning, you will notice that the higher you push the voltage, the less efficient the miner becomes from a power consumption standpoint. There is the potential as well that if your chips do not have enough voltage or balance of mHz, then the board will underperform or not hash. With experimentation, you will be able to find the proper balance.
Autotune will hopefully be a feature soon, but until then, have fun experimenting.