Question GPU is hotter after changing PCIE cable

[gtrabach]

Last week I cleaned my computer internally, and since then my GPU temperatures have risen considerably. If before they were at 38-40ºC at idle, now they are at 46-52ºC at idle.

At first I thought it might be a driver problem (I took advantage of the cleanup to update the drivers) so I reverted back to the previous driver but still the problem persisted.

I opened the computer again to check if there was any obstruction or if the card fans were spinning, and everything was normal. Disappointed that I didn't get an acceptable answer, I started using the computer normally. That's when I remembered that on that occasion, during cable management, I ended up using a different PCIE tip of my cable. My GPU uses 8 pins while the cable has two ends of 6+2 pins each.

I changed the end of the cable and to my surprise the temperatures normalized, returning to the same level as before.

How is this possible? Is one end of the cable faulty? I really can't figure it out, but this seems to be the cause of my problem.

Can anyone explain if this could really be the problem or if I'm just rambling?

Thanks

Specifications:
GPU: MSI RX 470 Gaming X 4Gb
PSU: Corsair RMX 750W (all cables are original Corsair)

For clarity:

 

[Eximo]

There would be some minor differences if you used the end farthest from the PSU. Being longer there would be a little more resistances, and the connections that join the cables together may not be perfect.

Only real way to be sure would be an infrared camera or indirect/direct temperature probes. If you can prove there is an issue, that might be something to take up with Corsair and get a replacement cable.

Or, if you are me and don't like daisy chained cables, just go out and get yourself a direct PSU to 8-pin cable from the likes of cablemod.

CableMod C-Series PRO ModFlex 8-pin PCI-e Cable for Corsair RM (Black Label) / RMi / RMx (600mm) – BLACK – CableMod

cablemod.com