[Knowledge Mining University Q&A] Why do mining machines need to be overclocked and underclocked?

Answer from @OWEN, editor of Zhikuang University:

After the rapid decline in the price of the currency on March 12, many miners shut down their machines, and the total network computing power dropped from 130EH/s to less than 100EH/s. Some miners also reduced the frequency of the mining machines that were originally shut down so that they could continue to mine with a slight profit. Some friends are curious why they reduce the frequency when the market is bad and overclock when the market is good? Why can frequency adjustment change the profit of the mining machine? Today we will talk about overclocking and frequency reduction of mining machines.

01
What is overclocking and underclocking

Overclocking and downclocking are relative to the normal working mode of the mining machine. Overclocking/downclocking essentially changes (optimizes) the mining machine chip algorithm and its voltage and current, thereby changing the power consumption and computing power of the mining machine. It can be simply understood that the mining machine can adjust different gears, and the low computing power gear, normal computing power gear and high computing power gear correspond to downclocking, normal and overclocking working modes respectively.

Of course, the premise of overclocking or downclocking is to have firmware that supports frequency modulation. Firmware can be understood as the operating system of the mining machine. Only with an operating system that supports frequency modulation can the mining machine achieve overclocking and downclocking.

02
The purpose of overclocking and underclocking

The purpose of overclocking and downclocking is to increase the profit of the mining machine. The net profit of the mining machine depends not only on the output value of the mining machine, but also on the electricity cost of the mining machine. In theory, if increasing the computing power of the mining machine can bring positive profits, that is, after increasing the computing power, the increased output value is greater than the increased cost, then overclocking is profitable and should be overclocked. On the contrary, if reducing the computing power can bring positive profits, in other words, after reducing the computing power, the cost decreases faster than the output decreases, then the frequency should be downclocked, and the limit of downclocking is shutting down.

For example, under the current circumstances, if a certain mining machine chooses the overclocking mode, the 24-hour output value of the mining machine will increase by 2 yuan, and the electricity cost will increase by 1.5 yuan. The net income of the mining machine in the overclocking mode will increase by 0.5 yuan per day, so the mining machine can choose the overclocking mode.

On the contrary, if the price of the currency falls and a certain mining machine chooses the frequency reduction mode, the 24-hour output value of the mining machine will decrease by 2 yuan, and the resulting electricity cost will decrease by 2.5 yuan. If the overall profit is positive, the mining machine should choose the frequency reduction mode.

Let’s take the S9 miner as an example:

Assuming that the current coin output per T computing power every 24 hours is 0.000019 bitcoins, the bitcoin price is 45,000 yuan/bitcoin, and the electricity price is 0.38 yuan/KWh, in the three working modes of underclocking, normal, and overclocking, the net income of S9 per day is: 0.64 yuan, 0.02 yuan, and -0.24 yuan respectively.

▲The above computing power and corresponding power data are from the actual measured data of the Litecoin mining pool

In the above case, the S9 mining machine will gain higher profits by adopting the frequency reduction mode.

Assuming other conditions remain unchanged and the price of Bitcoin rises to 80,000 yuan/Bitcoin, then the S9's daily net income in overclocking mode is the highest:

The frequency adjustment firmware of the S9 mining machine supports more adjustable gears. The above picture selects one in the underclocking area and one in the overclocking area. In addition, the frequency adjustment of the mining machine is very simple. You only need to select the gear on the mining machine control page. You can also use the supporting batch tools to realize batch selection of gears for multiple mining machines.

▲Different working gears can be selected on the mining machine control page

There is a special case where the mining machine has the highest profit when it is underclocked, but it is not underclocked, or even overclocked. This is definitely because the mining farm has signed an electricity agreement with the power plant before. If it is not used, it is equivalent to wasting the purchased electricity. It can only be used to fill the load. Or from another perspective, the electricity bill paid before is already a sunk cost, which cannot be recovered, so you have to use as much as you have, otherwise you will lose more money.

03
The impact of overclocking and underclocking on mining machines

The essence of changing the net income of the mining machine through overclocking and downclocking is to change the energy efficiency ratio of the mining machine. Let's use the S9 mining machine above to see the energy efficiency ratio under different working modes:

▲Energy efficiency ratio of S9 mining machine in different working modes

It can be seen that after the frequency of the mining machine is adjusted, the energy efficiency ratio does not change linearly. In order to maximize the profit, the working mode of the mining machine needs to be dynamically adjusted according to market conditions.

When the market is sluggish, the energy efficiency ratio of the mining machine can be reduced by downclocking, which can not only increase the net profit of the mining machine, but also reduce the shutdown coin price of the mining machine and improve the safety margin of the mining machine. On the contrary, when the coin price is high, although overclocking increases the electricity cost of the mining machine, the increase in profit is greater than the increase in cost, so overclocking can be used to increase profits and shorten the payback period.

Overclocking mode has a potential adverse effect on the stable operation and life of the mining machine. Overclocking is equivalent to running the mining machine beyond the rated load of the mining machine. If the mining machine is running in normal mode and the computing power is 5% or more lower than the theoretical value, the computing power is unstable, the board is dropped, the chip is incomplete, the output power of the power supply is insufficient, etc., it is not recommended to use the overclocking mode for the mining machine.

The frequency reduction mode has no adverse effect on the mining machine. As long as the mining machine can run in normal mode, it can run at a reduced frequency, which has no effect on the service life of the mining machine.

04
Things to note when overclocking or underclocking a mining machine

As mentioned above, the premise of overclocking or downclocking is to have firmware that supports frequency modulation, but this does not mean that all frequency modulation firmware can be used. Some frequency modulation firmware released by third parties may not only damage the mining machine, but may even have the risk of implanting viruses and hijacking the mining machine's computing power, which will ultimately cause losses to miners. The safest approach is to only use the official firmware released by the original mining machine manufacturer. When upgrading the firmware, you should also try one or two mining machines first to see the firmware stability and profit performance, and do network isolation. Once the mining machine is poisoned due to the firmware upgrade, the impact can be controlled to a minimum.

05
Summarize

The purpose of mining machine frequency regulation is to maximize profits. Its essence is to optimize the profits of mining machines by adjusting the energy efficiency ratio of mining machines.

The frequency adjustment of the mining machine is achieved in advance with adjustable frequency firmware, and it is best to use the firmware officially released by the original mining machine manufacturer. Overclocking affects the service life and working stability of the mining machine. Therefore, when overclocking the mining machine, in addition to considering maximizing the profit, the condition of the mining machine itself and the working environment temperature must also be considered. Overclocking can only be performed when all conditions are allowed.

If you know any other tips to increase miners’ profits, please share them in the comments section. If you have any questions about mining and halving, you are also welcome to ask questions to Zhikuang University.