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Old 2020-10-21, 18:52   #8
kriesel's Avatar
Mar 2017
US midwest

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Default Power settings

There are multiple reasons to configure for power usage.
One is to ensure the system continues to work on assignments with no user interaction.
Another is to optimize power efficiency.
Another is to reduce total power to levels within the system's current cooling capacity or power supply capacity, which may diminish over time, or to improve running temperatures.

Turn off what you are sure you don't need. Varies considerably by BIOS flavor. Then test for the maybes. Some candidates are onboard video, USB, PCIe, audio, serial or parallel ports if present, extra NICs.
Reducing maximum cpu clock rate can reduce power usage, and improve power efficiency.

To help the system stay up and running prime95 or mprime or whatever on the cpu, and any relevant gpu applications, at full tilt while unattended, modify the default OS power saving settings. Test by leaving the system on continuously after a restart.
For Windows 10:
click on the lower left Windows icon, the gear that will appear a bit above it, System in the pane that will appear, then "Power & sleep". Find "when plugged in, pc goes to sleep" and select "never".

Scroll down and find "additional power settings", click on it, then in the pane that opens, click change plan settings, then click "change advanced power settings". Adjust the many settings in the resulting window to the speed/power tradeoffs you want after considering utility cost.

Linux is reported to have lower overhead, so switching OS is a possibility.

Disabling unneeded services or applications helps.

Consider using the power limiting capabilities of nvidia-smi for NVIDIA GPUs, or the corresponding AMD GPU utilities, to reduce GPU power from maximum to a lower level that is more power efficient. Especially during the air conditioning season.

Misc. hardware:
Remove any unnecessary hardware that's removable. Unused GPUs, excess RAM, DVD or CD drives, extra HDs, etc all draw power at idle. (Although reducing the number of occupied RAM channels will reduce computing performance somewhat.)

Power supply:
Use high efficiency power supplies. Select for output rating ~1.7 times the expected usage, so that the system will run near the power supply's peak efficiency, and some room for growth in installed components.
If using UPSes, select for high efficiency

Locate the system in a cool area. Fans won't run as hard, saving some wattage. Lower temperatures improve both efficiency and component lifetime. Low locations (floor) tend to be cooler than elevated locations.

Dust, lint etc builds up on grilles, fan blades and heat sinks, reducing cooling effectiveness over time. Use clean dry air to blow it out, or an old toothbrush or other brush to loosen and remove it. Use necessary antistatic precautions.

Application features:
Power usage can be reduced by certain features of GIMPS applications.
Mprime/prime95 can use fewer cpu cores than the maximum, or use "throttle=", or both.
Reducing the frequency of saves to disk may help.
Application tuning may increase total wattage while raising throughput by a greater amount, improving power efficiency.
In CUDALucas and CUDAPm1, low values for "PoliteValue=" can be used as a form of GPU throttling.

(This post has been supplemented with content from and other sources.)

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Last fiddled with by kriesel on 2021-05-07 at 00:07
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