BAMT 0.5c - cgminer 2.6.1 - Litecoins - Motherboard burst into flames

[amencon]

Haha, from the title I'm sure you can guess I fucked something up good.

For fun I figured I'd try out mining some Litecoins in BAMT on my 4x GPU rig (5770, 5830, 2x 5850).

I started off using the settings for cgminer on the bitcointrading.com guide (which works great and I've since swapped back to):

"intensity" : "15,15,15,15",
"worksize" : "256,256,256,256",
"kernel" : "scrypt,scrypt,scrypt,scrypt",
"gpu-engine" : "620-725,620-725,620-725,620-725",
"gpu-fan" : "20-85,20-85,20-85,20-85",
"gpu-memclock" : "1000,1000,1000,1000",

I think I swapped the settings to something like:

"intensity" : "20,20,20,20",
"worksize" : "256,256,256,256",
"kernel" : "scrypt,scrypt,scrypt,scrypt",
"gpu-engine" : "900,900,900,900",
"gpu-fan" : "20-85,20-85,20-85,20-85",
"gpu-memclock" : "1250,1250,1250,1250",

The very instant I hit enter to restart cgminer after settings changed the computer powered off and smoke billowed out of the top of the case.  Looking around at side with the cover off the motherboard was on fire.  I've heard of this happening before but I didn't realize it be that instant.





The rig has paid for itself a long time ago and no other components got damaged so all in all not that big of a deal, but if your setting up something similar be careful how you setup cgminer if you don't want your motherboard on fire.

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Also I suppose this thread is as good as any to announce my Litecoin mining colocation service:

1. You send me your hardware
2. I choose the settings to maximize Litecoin production from your rigs
3. I have cheap electricity
4. We can share the profits

What could go wrong? PM for details!

[pekv2]

First things first, what PSU were you using?

[amencon]

Azza PSAZ-1000A14 Titan ATX 1000w 80+ Bronze.

[philips]

Don't forget to use powered risers next time...or you did?

[amencon]

Ah, no.

2x GPUs were plugged into the x16 slots.

For the 2 1x slots I'm using this:



Are powered risers always recommended?  Used this rig for bitcoins using BAMT for awhile and tested all sorts of settings.  Some auto shut down the system but never fried anything.

[philips]

There is a lot of power drawn from those PCI slots and they can only provide so much. (75 W...I think?)
GPUs are externally powered but not so the memory, the moment you cranked up the memory...poof (usually the ATX connector)

I was almost in the same situation, briefly switched to Litecoin and changed the memory clocks from 150 to 1200 (6 cards) but I was aware of the danger. Shortly after (1 min) the ATX connector (and the motherboard around it) got extremely hot and I stopped the rig. Close call.

Search the forum for powered risers or burned motherboards, you will find lots of horror stories.

(I would say that yes, for big/many cards and LTC mining you should use powered risers.)

[amencon]

OK awesome.  Thanks for helping me understand what happened.  I'll be sure to keep the memory where it is at for now until I can swap the risers for powered ones.

[philips]

Well, at least this what I think happened to your board.

[amencon]

Yeah don't worry I won't blame you if I burn it up again hah.

It does sound like a good theory to me.

[BitshireHashaway]

Dang that sucks. At least you managed to catch it. I heard about someone in Canada whose house burned down. Imagine if you had set it up like that, and then gone away for a few hours or something, because the fire didn't start instantly, imagine what could have happened.  How did you put out the fire?

[massnerder]

I am using the same board with 4x 7950's doing LTC and the exact same thing happened to me!

I spent all day setting it up just right for best hashrates, and about an hour after I left it sit to run I saw flames coming from my crate rig.  Luckily I was right here with it when it happened.

I also had 2 cards on the board and 2 cards on the non-powered riser cables.  My board was less than 24 hours in my hands though so I am getting it replaced and have ordered powered risers, though I am gonna be watching it very closely for a long time before I ever let it run unattended.

[philips]

Hey, we meet again 

[massnerder]

 

[clicksmoney]

You guise have the right kind of extinguishers for electrical fires?!?!

[silicont]

I wonder if powered risers are as big of a necessity when the 7970 cards take 6 + 8 pin PCIE power drops from the PSU?  Is such a card also pulling lots from the PCIE slots and needs a powered riser? 

I've been assuming these issues were on single PCIE power drops from the PSU, not the 6+8 pins.

Thanks

[philips]

The memory chips from the cards (and the fans, some of them 24W each) are drawing power from the PCIE slots, not from the cables whatever the type. Those are feeding only the GPUs.

For BTC mining you should be safe without powered risers (say up to 5-6 cards and with memory underclocked), but for LTC mining (which is memory intensive and causing higher temperatures) powered risers are a must for more than 3 cards.

[silicont]

Thanks, phillips.

[PeeJWeeJ]

Also I suppose this thread is as good as any to announce my Litecoin mining colocation service:

1. You send me your hardware
2. I choose the settings to maximize Litecoin production from your rigs
3. I have cheap electricity
4. We can share the profits

What could go wrong? PM for details!

I love how you add this after talking about accidentally setting a rig on fire. You may want to rethink your marketing strategy.