All you need to know about PC Power, PSUs, and Power Cables

A deep dive into PC power cables, what they do, what power they can carry and how to use them safely, so your beloved gaming rig doesn't catch fire. It covers the ATX12V motherboard cable, peripheral cables, the CPU/EPS cable and the various PCIE cables you may run into.
Incorrect cabling and over current can cause these cables to melt, burn and potentially cause fires. So its important to know what to connect to what, and what is safe.
0:00 - Cable Types
1:10 - PSU Types and efficiency
2:21 - PSU Sockets and cable compatibility
3:37 - ATX12V 24 PIN and Motherboard power
5:52 - Power delivery between PSU and components
7:00 - SATA Cables
7:35 - 4 PIN Peripheral ('Molex') cables
8:50 - 4, 4+4, 8 PIN CPU/EPS cables and power delivery
10:40 - EPS vs PCIE cables and connectors
11:20 - PCIE Cables, plugs, power capacity and limitations
15:30 - AWG and Cable Gauge

[@rcwagon]

Informative and well done. One comment, Using a larger wire in a cable (smaller AWG #) will have the effect of delivering more voltage to the load. There is some voltage dropped in the cable due to the wire's resistance (power = IR {Current squared times Resistance of the cable}). Bigger wire = smaller resistance - less power dropped in the wire, slightly higher voltage at the load.

[@sometechguy]

Thank you, good clarification.

[@BigPlonkerAlt]

Great video, thank you!

[@sometechguy]

🙏

[@burellyt]

Nice job, informative but a bit underdeveloped. For example, I have a 'be quiet' 13 1000 psu with pcie ports that are 12 pin. As well there are a couple of P8 ports with 10 pins. You didn't mention anything about that possibility or what the difference is between them.. Also when discussing the sata ports on the psu, the ones on your psu are two rows of 3 whereas my psu has a single row of 5 pins. Lastly, if I wanted to use the connection on the m/b for the additional power (the one next to the 24 pin connector) I would need a 6 pin connector but my psu does not have any 6 pin ports so i would need an adapter? And where would I attach such cable to the psu? Again, great job, but could use a look at several more psu's.

[@sometechguy]

At the PSU end, each is going to vary and those connectors can be proprietary. It’s important to use cables for that specific PSU (and even model). At the other end, everything needs to comply with standards, so they should present a 20 or 24PIN ATX cable, and then 6/8PIN pcie and 8 PIN EPS/CPU as well as Sata and usually sole ‘Molex’.
So not sure on the connector types or pin outs on your BeQuiet but the Motheboard end should be the same, and you would use a PCIe 6 pin for that additional plug next to the 24PIN, and of course CPU/EPS 8 pin for the sockets for the CPU portion.
If you are out of PCIe cables for that supplementary connector, you can get converters for EPS to PCIe as they are all 12V, but be careful you have the right adapter, check the PIN outs with the seller and don’t force it if it won’t fit. But usually if you are running a rig that is calling for supplementary power then you would run a beefier PSU that would have the addition cables. That supplementary connector is really only needs of you are pulling lots of power off the motherboard via PCIe, for example, 2 GPU, which is pretty rare there days.
Thanks for the feedback, and watching.

[@abreu7756]

thx

[@sometechguy]

👍

[@b_u_x402]

Can you help ...my pc works 100% but somtimes it just doesn't power on at all ..idk why that happens

[@sometechguy]

Very hard to say from the description. Check everything is plugged in thoroughly and see if you get any beeps from the computer at startup. Different numbers of beeps indicate different problems with the start sequence. Make sure the PSU provides enough power for the components you have. Also, if the problem started after you added or changed something, that's an indicator.
If it isn't starting at all, and you have more than 1 memory module installed, you can try it with 1 at a time to see if its faulty RAM, and make sure the RAM is all seated correctly. If you can get to BIOS, try doing a BIOS update or reset the BIOS settings in case you made a bad change there.
But its a bit of a vague question, so could be many things. Good luck with it!