Dummy Plugs/ Multiple GPUs

[sir murray]

I don't really understand this totally. Any GPU I plug in for mining other than the one attached to the primary monitor will remain unavailable for mining in windows? If this is so, does cycling the monitor through the GPUs activate them for mining? These steps would work?

1. Install 3 GPUS

2. Start mining on 1st GPU.

3. Switch monitor to 2nd GPU, start mining.

4. Switch monitor to 3rd GPU, start mining.

This would allow me to run all 3 GPUs without a dummy plug in 2 of them, right?

[keybaud]

I don't really understand this totally. Any GPU I plug in for mining other than the one attached to the primary monitor will remain unavailable for mining in windows? If this is so, does cycling the monitor through the GPUs activate them for mining? These steps would work?

1. Install 3 GPUS

2. Start mining on 1st GPU.

3. Switch monitor to 2nd GPU, start mining.

4. Switch monitor to 3rd GPU, start mining.

This would allow me to run all 3 GPUs without a dummy plug in 2 of them, right?

For Windows, yes, but every time something hiccups you have to do it all again. Just sticking a single resistor into the HDMI socket does make it a lot easier.

[sir murray]

Would sticking a DVI cable to the monitor in the 2nd GPU, and sticking an HDMI cable to the same monitor in the 3rd GPU work the same?

[gamecom]

I'm mining with on Windows my two 5850's and didn't ever thought about need to use the dummy plugs, it isn't needed!
You just need to disable ULPS - this mechanism disables the second card without monitor/workload. Here's how to do it:

Go to registry and disable Ulps:

 [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Contro l\Cl ass\{4D36E968-E325-11CE-BFC1-08002BE10318}]

 and change "EnableUlps" to 0 under the 0000 and 0001 or 0003 keys.

[Chucksta]

Would sticking a DVI cable to the monitor in the 2nd GPU, and sticking an HDMI cable to the same monitor in the 3rd GPU work the same?

Yes it would, and I have done that in the past.

I now use a KVM.

If you happen to have enough monitors in your place, you could temporarily attach them to the GPUs prior to start up. Once you are in windows, you can then remove all the monitors you don't want to use on that system and put them back where they came from (wife's PC, Kid's PC, etc). Now windows will see all your GUPs even though they have nothing plugged into them

KVM ftw... 1 monitor, 1 keyboard, 6 GPUs

[padrino]

I had the same issue but didn't need to do anything in hardware, only software. Not sure if this applies to your setup but it did work for mine (2x5770s) so you may have some luck. I went into the monitor configuration (screen resolution in Windows 7) and enabled my desktop to extend to the display showing from the second card. Nothing is plugged into the card but it did enable it, I set it to 800x600 and moved it to the upper right corner so I don't move into it by accident often.

[Chucksta]

I'm mining with on Windows my two 5850's and didn't ever thought about need to use the dummy plugs, it isn't needed!
You just need to disable ULPS - this mechanism disables the second card without monitor/workload. Here's how to do it:

Go to registry and disable Ulps:

 [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Contro l\Cl ass\{4D36E968-E325-11CE-BFC1-08002BE10318}]

 and change "EnableUlps" to 0 under the 0000 and 0001 or 0003 keys.

Awesome, you are the man !

Noted, just in case of future development

[sir murray]

I'm mining with on Windows my two 5850's and didn't ever thought about need to use the dummy plugs, it isn't needed!
You just need to disable ULPS - this mechanism disables the second card without monitor/workload. Here's how to do it:

Go to registry and disable Ulps:

 [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Contro l\Cl ass\{4D36E968-E325-11CE-BFC1-08002BE10318}]

 and change "EnableUlps" to 0 under the 0000 and 0001 or 0003 keys.

Cool very useful. So I can do this, restart windows, and I can mine with all the GPUs?

[bulbur]

Can anyone confirm that this works?

[qed]

Can anyone confirm that this works?

Not working at all for me.

[allinvain]

If the registry hack works it would mean I just bought 4 dummy plugs for nothing

Anyone tried it on Win 7 64 bit?

[airdata]

I'm mining with on Windows my two 5850's and didn't ever thought about need to use the dummy plugs, it isn't needed!
You just need to disable ULPS - this mechanism disables the second card without monitor/workload. Here's how to do it:

Go to registry and disable Ulps:

 [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Contro l\Cl ass\{4D36E968-E325-11CE-BFC1-08002BE10318}]

 and change "EnableUlps" to 0 under the 0000 and 0001 or 0003 keys.

Sir, you're a gentleman and a scholar.  I'll try that later.  Although I spent $16 and ordered 20 vga/dvi dongles and 100 capacitors to make the ghetto rigged dummy plug.

Not that I don't love having hdmi-hdmi for my main system, hdmi-dvi for gpu1 on miner and vga-vga/hdmi dongle - hdmi for gpu2 on miner

[chiropteran]

I'm mining with on Windows my two 5850's and didn't ever thought about need to use the dummy plugs, it isn't needed!
You just need to disable ULPS - this mechanism disables the second card without monitor/workload. Here's how to do it:

Go to registry and disable Ulps:

 [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Contro l\Cl ass\{4D36E968-E325-11CE-BFC1-08002BE10318}]

 and change "EnableUlps" to 0 under the 0000 and 0001 or 0003 keys.

Awesome, I just ordered some new parts and forgot about the whole dummy plug thing, if this eliminates the need for them I won't have to bother.

[tito13kfm]

I've had EnableUlps set to 0 for quite some time (Crossfire related problem with 1 card randomly going to 0% load).  I can confirm that this will NOT allow you to start mining on a GPU that doesn't have a monitor attached.

My solution.  My monitor has 3 inputs.  I plug my 2 cards in to it.  1 DVI 1 DVI-VGA.  Start mining and overclock 1st card, hit switch input, start mining and overclock 2nd card.

[innervisi0nn]

I don't really understand this totally. Any GPU I plug in for mining other than the one attached to the primary monitor will remain unavailable for mining in windows? If this is so, does cycling the monitor through the GPUs activate them for mining? These steps would work?

1. Install 3 GPUS

2. Start mining on 1st GPU.

3. Switch monitor to 2nd GPU, start mining.

4. Switch monitor to 3rd GPU, start mining.

This would allow me to run all 3 GPUs without a dummy plug in 2 of them, right?

Just build a dummy plug, all you need are some resistors and a dvi/vga adapter/port.
I used to do this, but everytime my PC would restart or power went out, it was a bitch doing this every day!

Dummy plugs, no worries!

[tito13kfm]

Just build a dummy plug, all you need are some resistors and a dvi/vga adapter/port.
I used to do this, but everytime my PC would restart or power went out, it was a bitch doing this every day!

Dummy plugs, no worries!

My linux server has 186days uptime.  Where do you live that power goes out that frequently?

[BitCheddar]

Cheaper and simpler dummy plug.

http://www.overclock.net/folding-home-guides-tutorials/384733-30-second-dummy-plug.html

[innervisi0nn]

Just build a dummy plug, all you need are some resistors and a dvi/vga adapter/port.
I used to do this, but everytime my PC would restart or power went out, it was a bitch doing this every day!

Dummy plugs, no worries!

My linux server has 186days uptime.  Where do you live that power goes out that frequently?

Its not about where I live lol..its my damn apartment circuit at home...1.2 ghash takes alot of power with these damn 5830s..i plug a hair dryer in and blows the circuit..

[allinvain]

Umm that's nuts. You may want to put the miners on a separate circuit if possible. If for some odd reason you're running everything in the apartment off of a single circuit then whoever wired that apartment should be shot.

[gamecom]

I've had EnableUlps set to 0 for quite some time (Crossfire related problem with 1 card randomly going to 0% load).  I can confirm that this will NOT allow you to start mining on a GPU that doesn't have a monitor attached.

My solution.  My monitor has 3 inputs.  I plug my 2 cards in to it.  1 DVI 1 DVI-VGA.  Start mining and overclock 1st card, hit switch input, start mining and overclock 2nd card.

Did you set it up on all cards eg. under the 0000 and 0001 or 0003 keys? It works fine for me, my config:
Windows 7 x86
HIS Radeon 5850
ASUS Radeon 5850 DirectCu TOP
Latest catalyst drivers.
CrossFireX enabled
Cards are linked with CrossfireX bridge. If it still doesn't work, there's another solution, run furmark or another GPU heavy application for a minute, then the second GPU will appear ready for mining - I was doing this before learning the ULPS trick.