5. GENERAL RECOMMENDATIONS FOR OVERCLOCKING AND VOLTAGE LEVELS ON AN ADDITIONAL POWER SUPPLY
As a starting point you can use the preset profiles ① and voltage values ② for the additional power supply, which can be found in the tab Configuration > CGMiner configuration > Overclock
If no profiles exist and no recommended values are available, refer to the stock voltages and frequencies.
For this, turn on the unmodified miner and wait for it to enter the operating mode (usually 20-40 minutes). Use the original factory firmware or the BiXBiT firmware with Normal profile. Then check the status page in the miner's web interface.
In further computation we need ① (V_normal), ② (F_normal).
The value 1.412 in this example means a voltage of 14.12 volts.
Leave the miner running, measure the voltage on the hash boards.
Denote the measured voltage as Vmain
Vmain = 13,83 В
The values are calculated using the common formulas for overclocking (where Percent is the percentage of frequency increase, it approximately reflects the percentage of miner overclocking):
Target Frequency = F_normal * (Percent + 100) / 100;
Target Voltage = V_normal * (Percent / 5.0 + 100) / 100;
Minimum Voltage = Target Voltage - 50
Maximum Voltage = Target Voltage + 50
In case the parameters are out of the allowable limits, put the nearest possible value.
In case of power supply errors due to overcurrent, reduce the Maximum Voltage.
PSU Power Limit = 3900
3900 is a general value when overclocking with an additional power supply. But in some cases it may differ, depending on the specifics of the miner and its power supply.
PSU Power Max = PSU power limit +200
Denote the voltage on the additional power supply as Vpsu_add
On the initial setup of the additional PSU:
Vpsu_add = Vmain * (Percent / 5 + 100) / 100
During the subsequent tuning, Vpsu_add is set under load and equal to the voltage of the main power supply Vmain. That is, the measurement and adjustment must be carried out after the miner has entered the operating mode, keeping the power on.
For efficient miner overclocking, the hash board frequencies that are set by the miner after the autotune is complete, and the voltages of the additional and main PSU should be as similar as possible
The example of overclocking you can see in section 6.
The computed values must be set in the Overclock tab. Make sure the Advanced Options checkbox is ticked.
The general algorithm for overclocking is as follows:
Actions to be taken for the initial setup:
- Check the Miner readings running in stock and note the voltage of the main PSU at that moment.
- Do the calculation according to the formulas.
- Install the BiXBiT firmware and connect the additional power supply
The following steps should be repeated until the necessary result is reached:
- Set the new values on the Overclock tab
- Set the voltage of the additional power supply according to the Vpsu_add calculated voltage
- Turn on the miner and wait for the miner to enter the operating mode.
- Measure the voltage of the main power supply Vmain. V_main is measured at points ① and ②.
- Keeping the miner running - adjust the voltage of the additional power supply to the voltage of the main power supply.
- Restart the miner.
- In case the frequency on the board with the additional PSU turns out to be significantly lower (more than 50) than on the boards powered by the main PSU, it is necessary to additionally increase the voltage Vpsu_add
- If the frequency and hashrate on the board with the additional PSU appears to be significantly higher - you can further increase the Target Voltage / Target Frequency in the overclocking settings.
- If errors occur - the voltage and frequency values must be reduced