Power cables and connectors
Whether you are a seasoned veteran or a newcomer to the the server system building it is essential to understand the various power cables and connectors required to safely power PCIe computing units such as GPU.
So we made an summary to ensure that the system runs smoothly without any crashes, and will also prevent potential disasters like electrical fires or damaged hardware.
Different Types Of Gpu Power Connectors
GPU consume power from PCIe and power cables, in general, PCIe bus supports 75W of power.
| Connector type | Max. Power[1] | Idel for | Notices (Picture from cgdirector)[2] | |
|---|---|---|---|---|
| PCIe 6-Pin | 75W | Old GPU | 
|
|
| PCIe 6+2 or 8-Pin | 150W | <300W GPU | 
|
|
| CPU EPS-12V (EATX12V) | 8pin (336W)
4pin (168W) |
<300W GPU |  |
|
| 12VHPWR | 150/300/450/600W | RTX 3000/4000 series |  Designed for Gen-5/ATX 3.0 PSUs
Gen-4/ATX 2.0 needs an 8-pin to 16-pin 600W 12VHPWR adapter |
12VHPWR sindband
The sideband signals SENSE0/SENSE1 definitions, which signal maximum available power available from the PSU, have been updated, as shown in Table 3-6.
Power/Ground Pin Wire Size: 16 AWG
Sideband Signals Pin Wire Size: 28 AWG
- The 150 watts power level now requires the SENSE0/SENSE1 pins to be shorted together in the power supply or the cable.
- When both SENSE0/SENSE1 are unasserted, as defined by their high-impedance Open-Open state, no power may be drawn by the load. This is new SENSE0/SENSE1 combination now defines the new 0 watt state, which was not present in the 12VHPWR connector. These updated SENSE0/SENSE1 combinations ensure that an Add-in Card may only draw power only when the power pins and the sideband pins are engaged and correctly asserted. The Open-Open condition signals that the PCB plug is either poorly seated or absent. These two conditions are now functionally equivalent. A PCIe CEM 5.1 Add-in Card will explicitly interpret the Open-Open SENSE0/SENSE1 stat as the 0 watt configuration, and it will not attempt to draw power from the cable.
It is important that the power supply provide these updated SENSE0/SENSE1 encodings to the cable, to ensure compatibility with PCIe CEM 5.1 compliant Add-in Cards. See 3.3.1 for more details on SENSE0/SENSE1 encoding.
Different Types of Cable
There are two popular wire size standards, AWG (American Wire Gauge) and Metric Wire Gauges[5]
It is important to know cable spec of your power connection to GPU or other devices to avoid potential disasters like electrical fires or damaged hardware.
18 AWG cable is widly used for GPU power cable at the time of writing this page.
References
- ↑ https://www.gpuminingresources.com/p/psu-cables.html
- ↑ https://www.cgdirector.com/gpu-power-cable-guide/
- ↑ https://videocardz.com/newz/pcie-gen5-power-connector-is-compatible-with-geforce-rtx-30-founders-edition
- ↑ https://www.techpowerup.com/forums/threads/intel-atx-3-0-16-pin-power-connector-for-pcie-gen5-is-smart-has-four-power-delivery-variants.292563/
- ↑ https://www.powerstream.com/Wire_Size.htm