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Other => CPU/GPU Bitcoin mining hardware => Topic started by: TwinTurbo on July 21, 2012, 08:05:10 AM



Title: Three Dead 5850s At Once?
Post by: TwinTurbo on July 21, 2012, 08:05:10 AM
So I hooked up 4 HD 5850s to a 850W power supply, but was short on PCI-E connectors. To make up the difference I used two molex to PCI-E adapters and ran them to two different cards. I ran out of PCI-E splitters. These adapters had two molex connectors each into one PCI-E. I hooked up both of them for each adapter.

I turned on the machine and nothing came on. I believe the fans spun, but no post. One card out of the 3 seemed to survive whatever it was that happened to these cards. The cards are Visiontek reference series and I don't have the invoice for warranty, they're expired. Is it possible that something more simple happened to them, such as the BIOS got wiped out or something by some power protection mechanism?

I'd love to recover these cards if possible. Any thoughts on what might have happened/how I can possibly diagnose them via DOS utilities or something?

Thanks!


Title: Re: Three Dead 5850s At Once?
Post by: Coinoisseur on July 21, 2012, 08:09:06 AM
What specific model of power supply?


Title: Re: Three Dead 5850s At Once?
Post by: check_status on July 21, 2012, 08:41:10 AM
What Coinoisseur says...+ What mining software, OS are you running?

Manufacturers aren't going to add more copper to allow a wire to handle double if they don't feel it is a need. They design with the amount of copper for the job of the connection and it's power needs, no more. So, if you have exceeded the electrical requirements of the system with your setup, it will bug out, harm the devices, or harm the system.

I would just connect straight to the power supply one card at a time and test to see how each card is functioning. If the card runs, let it hash and play with the clocks to see how it responds.


Title: Re: Three Dead 5850s At Once?
Post by: TwinTurbo on July 21, 2012, 09:26:07 AM
What specific model of power supply?

The power supply is: http://www.newegg.com/Product/Product.aspx?Item=N82E16817194093&Tpk=lepa%20850w

This power supply works well for powering four 5870s in several of my other machines, but in that case I used PCI-E splitters.

Software is irrelevant, the machine never even made it to boot. Something shorted somewhere along the way. This was in an MSI 890FXA-GD70 board. The motherboard was unaffected, as it powers 4 other cards today without issue (not using Molex this time).


Title: Re: Three Dead 5850s At Once?
Post by: AndrewBUD on July 21, 2012, 12:47:25 PM
That psu should be enough. I ran 4 x 5850 on a corsair HX750.....


Title: Re: Three Dead 5850s At Once?
Post by: Coinoisseur on July 21, 2012, 03:19:11 PM
It's a multi-rail PSU, so you probably just overdrew on a rail. Need to distribute power to keep under each rails Amp rating.