No, you cannot mix PSU cables. Although the connector that goes on the component side has standardized pinouts, there is no standard for connectors on the PSU side.
If you try mixing cables, one of these three cases is possible.
- The cable does not fit at all.
- The component connected via that cable does not turn on.
- Or, you end up blowing that component.
Let’s discuss in detail the possible consequences of mixing the PSU cables.
Why Isn’t It Safe to Mix PSU Cables?
In most cases, you won’t even be able to fit a cable from one PSU into another. Here’s an example.
Still, if you managed it somehow, that’s not going to work. Let me quickly demonstrate why.
Here are two Molex cables—one from the EVGA SuperNova 650 G3 and another from the Corsair RM850x.
The Molex connector on the component side has one +5V DC pin, two GND pins, and another +12V DC pin. This is a standard pinout specified by ATX and is the same across all the PSUs.
But if we look at the PSU side, the pin configuration is completely different.
The difference in the wiring standards strictly prevents you from mixing up the cables. But how?
To know the reason, let’s connect both the Molex cables to the Corsair PSU and find the voltage readings.
Upon testing, the Molex cable from Corsair gave the standard results. No wonder! The PSU cable from Corsair will obviously work fine with the Corsair PSU. I was getting 5.09V in +5V DC pin.
However, the voltage reading on the EVGA’s Molex connector was completely different. I instead got 3.32V. That is not the desired voltage for a +5V DC pin.
While this is just one example, there might be multiple such scenarios.
For instance, you may get +5V in the pin that is supposed to be grounded or +12V in a +5V pin. Anything is possible depending upon the wiring standard of a PSU.
If the GND pin gets voltage, you will end up blowing your component. In fact, it can also take your PSU along.
On the other hand, if a voltage pin gets grounded, your component may not even turn on.
It does not matter if your PSU has OCP/OVP/OPP or SCP. These safety mechanisms won’t protect your PSU from failures due to the mixing of cables.
This not only holds true for your Molex connector, but for the CPU connector, PCIe connector, and rest of the power supply connectors too.
Now what if the voltage readings come according to the ATX power supply pinout?
The answer is still NO. You never know if the pin arrangement of the cable you are planning to use matches with the pinout of the original cable.
So mixing PSU cables is always a big no-no.
When Is It Safe to Mix PSU Cables?
The only time you can mix PSU cables is if it is from the same model/manufacturer.
Similarly, there won’t be issues mixing cables from another manufacturer if you are just looking for an extension.
The extension cables attach to the component side connector which is always standardized.
Some reputed companies like Corsair and EVGA also provide a list of PSU cable compatibility. You can access the list and verify if the cable will work with your PSU.
If you don’t see your PSU listed there, kindly contact your manufacturer.
