Bitcoin Forum

Other => Beginners & Help => Topic started by: d3m0n1q_733rz on June 12, 2011, 05:42:53 PM



Title: Use of 4x HD6990 cards
Post by: d3m0n1q_733rz on June 12, 2011, 05:42:53 PM
Hello, I am looking at building a rig with 4x HD6990 cards in it and I wanted to know if I would be required to connect each card to a display before their GPUs would be activated for mining.  I know in past calculation programs, it was required for a display or null to be connected to at least one port of each card before the GPUs would do any work; has this changed with OpenCL or do I need to invest in null devices?

Thanks!


Title: Re: Use of 4x HD6990 cards
Post by: muyoso on June 12, 2011, 05:49:27 PM
You could take a single monitor and plug it into the first card, start the miner and then plug it into the second card and start that miner, etc.  But you would have to do that each time you restarted the miners.  Would save a bit of money though.


Title: Re: Use of 4x HD6990 cards
Post by: trentzb on June 12, 2011, 05:52:01 PM
On Windows I believe it is necessary to connect a monitor or dummy plug to each card. On Linux it is not necessary.


Title: Re: Use of 4x HD6990 cards
Post by: phillipsjk on June 12, 2011, 06:10:45 PM
Apparently the "dummy plug" can consist of a strategicly placed 87 Ohm resistor (one of the color channels (say green) -> ground))


Title: Re: Use of 4x HD6990 cards
Post by: jwzguy on June 12, 2011, 06:14:42 PM
Dummy plug didn't work for me. Also, although I bought an MSI 890FXGD70 (quad xfire supposedly), installing more than 3 cards gave errors with MSI Afterburner. Not worth it, just have to put the 4th card into another machine.



Title: Re: Use of 4x HD6990 cards
Post by: arc45 on June 25, 2013, 01:38:43 AM
On Windows I believe it is necessary to connect a monitor or dummy plug to each card. On Linux it is not necessary.

Thanks for saying that.  I was wondering why my pc couldn't see the 5870.


Title: Re: Use of 4x HD6990 cards
Post by: galtbit on June 25, 2013, 03:31:59 AM
hmm..


Title: Re: Use of 4x HD6990 cards
Post by: xide on June 25, 2013, 05:44:39 AM
dummy plugin depends of driver version...