Topic: [WARNING] USB Riser Fire Hazard (pics included) (Read 1141 times)

I had that issue way back when, I got a bunch of molex to 6 pin adapters but found even though the wire was marked 18 AWG it was more like a 26 AWG , outer diameter of the insulation was right but not the wire, gets you thinking when your at work and wires start burning. Of course those cool PCIe risers didn't exist like that either.

Definitely, lessoned learned!

Great question!

These were 6-pin R9 370s

Always use risers with molex connectors, they will handle much more wattage.  Those little floppy drive or whatever connector as you have seen melt pretty easily.

In all fairness, as miners we're on the way extreme end of the spectrum for GPU usage.  I have 2x RX480's in Crossfire to use with my Oculus Rift (although I'll turn them on the mine occasionally), and the extra draw of a card or two doesn't amount of much in your higher end gaming system.  Toss 6 of them in a system, and then it's a bit different story...

i'm was never a fan and never will be of the reference board, for a reason

but since time is money many are buying it regardless

Definitely true, but also a good idea to user miner-grade cables whenever possible... I custom make mine myself although I think I'll be getting them done by a 3rd party soon.  18AWG in a pinch, but I try to have everything 16AWG as much as possible - it's just not worth trying to save a couple of bucks and end up loosing a card or rig.

Yes and no ... AMD has fix the driver to reduce the load of the RX 480 on PCI-E slot.
But they just save a few Watt to be at the limit ... wich is already high if you run multiple cards on the mobo ... and risky if you use riser with low powered capacity.

The best is to wait RX 480 with 8 PIN

if it was really fixed and not too much oced in thiscase, the gpu should get the majority of the wattage from the pci 8 pin and not the riser anymore, it should limit itself tot he maximum the riser can provide, to prevent damage

the molex here would have saved his ass instead of that crappy floppy cable, it seems that even after the fix they still pull a minimum which is too much for that floppy cable so above 36w probably...

this also mean that on a standard ribbon riser x1-x16 it would melt... so other gpu are pulling much lower than 25w there

I believe so, but my point in listing those max power values was that even if the card is running within spec, with a riser you're already beyond the spec'd max of the connector (whether it be floppy connector or molex).

wasn't the problem with the "more than 75w" from the pcie, solved already with amd last fix?

Actually, I don't think this really matters - consider all the news about the RX480 consuming more than 75W of power off the PCI bus side.

Consider what the spec has as limits for the different connectors:

## The floppy connector that they use to connect to the riser is max 36W
## The those SATA connectors they give a table for are max 54W
## The more traditional 4-pin Molex is 60W
## The miner-staple 6-pin PCIe is rated at 75W
## The GPU specific 8-pin PCIe is rated at 150W

So that's why you see the problem with something like the RX480 - it's already pulling more than 20% over what a Molex-based riser is spec'd to supply.

Keep in mind that it's certainly possible to pull more power over many of these connections, but you're limited by your weakest link.  If your Molex cable has 22AWG wire, then the wire is probably going to fail before the connector - but if you're running 16AWG (miner grade) PCIe cables and are pulling 150W+ off of a 6-pin PCIe, then it's probably going to be the connector housing that fails (which is what you see in your example).

So the moral of this story is be aware of whatever you're plugging in, and do some monitoring of power consumption of each new type of card so you know what it's general characteristics are, and whether it should be something you keep an eye on or not.

Just curious, did you use these with cards which doesn't have 6 or 8 pin aux pcie power going into them?

https://www.amazon.com/gp/product/B014ZTVZB4/

I ordered these a while ago. Had issues with a rig freezing and went to check connections and found burnt cables in same spot for all the risers. I would recommend the molex connection not that puny thing that is a fire hazard (i.e. http://www.ebay.com/itm/172226185366). Just thought I would share since lots-o-people ask about usb risers. Luckily only had one rig set-up with these.

http://imgur.com/mCyKbIX
http://imgur.com/yXMDe7P