My Wires Are Burning: Update.

The wires here are starting to discolour.

Last week I put up a post complaining I’d burnt out some wires on a molex feeding a trio of RX480 cards.

Well this morning, I lost an R9 295X2 card in a rig which suddenly stopped working. I’ve learnt that if something stops working for no reason, it’s probably best to inspect wires first rather than last, so I had a look. They were a charred mess. I mean a real, total burn out. The insulation was gone, much of the copper was burnt through, and the connectors going into the cards had melted so much even the female connectors on the card itself had been damaged.

This is all that was left of the wires to the 295X2

The PSU was an 850w Corsair. The cables had been switched out by a previous owner, for some very pretty after-market red alternatives. There isn’t much left of those now. Whoever made those wires obviously put form before function, as the cables within clearly did not contain enough copper to actually supply a high draw PCI-E graphics card.

At this point, having started to notice a trend, I took to inspecting the wiring on every rig I own. There was some damage to the connector on a 7990 rig. The next 295X2 also had some discolouration around the 8-pin connectors, and that was on it’s own dedicated stock 1200w Corsair supply- with the load split across two separate rails. That suggests that even high end supplies simply don’t use a large enough wire to consistently stand up to the load of a single 295X2.

That 295X2 will have been pulling around 180w down each PCIE 8 pin. The problem with mining is the sustained currents really put a strain on wires, so where it may seem fine at first, as the weeks pass the damage builds and eventually things burn out and fail. It’s a real shame as a high end power supply really ought to be able to cope with demand from a high draw card, but apparently not. Perhaps what I considered high end simply isn’t high end enough. I think at the level of 1200w, Corsair really should have supplied better cables.

The conclusion here is inspect your wiring regularly. I will now make a point of inspecting all high-draw wires on a weekly basis across my farm. I’ve been lucky so far that these wires have burnt through without a flame, but the day may come when i’m caught with my pants down trying to piss out a fire. Inspect your wires folks!

1 Comment

  1. I had the same issue. I used a dedicated Super flower 1000 Watts for that GPU and I ran out off PSU cables, all have been burnt/charred. Now I’ve been using a Seasonic one but cables are starting to melt as well.
    I think PSU manufacturers do not expect this level of power to be drawn from a single cable.

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