Question on installing a 2nd card drivers-wise, 5870 w/ 5970

[Cablesaurus]

I'm going to be installing a 5870 into a box that's already mining with a 5970.

What's the best way to handle this drivers-wise? Should I just stick the 2nd card in and it will detect, or should I do a full uninstall of the drivers package and reinstall [which version if so?]

Thanks.

[FoS]

Hi, I have just installed 2nd card few days ago and I hadn't to re-install drivers. It detects 2nd card automaticly but I had to use a dummy plug for enable OpenCL in the 2nd card.
I use 11.2 in W7 32bits.
Anyway you could uninstall drivers package and reinstall it to be sure

[allinvain]

Hi, I have just installed 2nd card few days ago and I hadn't to re-install drivers. It detects 2nd card automaticly but I had to use a dummy plug for enable OpenCL in the 2nd card.
I use 11.2 in W7 32bits.
Anyway you could uninstall drivers package and reinstall it to be sure

Hey FoS do you know where I can get a dummy DVI plug or how I can easily make my own? I'd rather just buy one, and maybe even with BTC if I can find someone here.

I'm planning on building a dual 5870 mining rig and I'm pretty sure I'm going to need one of these dummy plugs even though I intend to hookup a monitor to the machine.

Edit: Hmm. I think I may have been wrong about needing a dummy plug. I think that all I need is _A_ monitor plugged in or a dummy plug but not both.

[FoS]

Yes, a dummy plug is to simulate a 2nd monitor. As I have only 1 monitor I must tu use a dummy plug in the second card.
Here you have to make easyly a dummy plug only with the dvi-vga adaptor and some resistors.
http://www.geeks3d.com/20091230/vga-hack-how-to-make-a-vga-dummy-plug/
There you have the electronic scheme for the resistors.

[allinvain]

Yes, a dummy plug is to simulate a 2nd monitor. As I have only 1 monitor I must tu use a dummy plug in the second card.
Here you have to make easyly a dummy plug only with the dvi-vga adaptor and some resistors.
http://www.geeks3d.com/20091230/vga-hack-how-to-make-a-vga-dummy-plug/
There you have the electronic scheme for the resistors.

I see. Thanks for the info. Time to see if I can find some 50 - 150 ohm resistors.

[Garrett Burgwardt]

I mine with an exactly similar box, and I just enable crossfire and don't need a dummy plug. Works fine.

[Jaime Frontero]

I mine with an exactly similar box, and I just enable crossfire and don't need a dummy plug. Works fine.

i think it depends on your OS.  windows or linux?

[allinvain]

I mine with an exactly similar box, and I just enable crossfire and don't need a dummy plug. Works fine.

i think it depends on your OS.  windows or linux?

I for one intend to use Windows 7 Ultimate 64 bit.

I found another guide to building a dummy plug:

http://soerennielsen.dk/mod/VGAdummy/index_en.php

The thing with crossfire is that I read on the forum that it decreases performance a little bit. I think for a dedicated miner squeezing as much out of the hardware is very important. But TheKid if you can assure me that performance won't suffer *that* much, or even give me some numbers to consider  (ie with crossfire and without), then I'll definitely not bother building a dummy plug.

[FoS]

I mine with an exactly similar box, and I just enable crossfire and don't need a dummy plug. Works fine.

Yes, but I have a 5850 and a 5770 so I couldn't do crossfire and I have to use the dummy plug.

[allinvain]

I mine with an exactly similar box, and I just enable crossfire and don't need a dummy plug. Works fine.

Yes, but I have a 5850 and a 5770 so I couldn't do crossfire and I have to use the dummy plug.

Riiight, now I get it. OK, well in that case I think I will stick to just linking the cards via Crossfire. I see no point in complicating things if I do not have to.

[ataranlen]

I'm running two 5970's. I don't use dummy plugs, When it detected and installed the second card, but didn't allow for mining, I un-installed all 4 gpu's but kept the drivers. Windows rebooted (twice I think), and now all 4 GPU's are available for mining. This has worked for three separate installs.

[kindle]

I'm running two 5970's. I don't use dummy plugs, When it detected and installed the second card, but didn't allow for mining, I un-installed all 4 gpu's but kept the drivers. Windows rebooted (twice I think), and now all 4 GPU's are available for mining. This has worked for three separate installs.

Hi I am curious could you lay out the order in which u carry out this trick?

[ataranlen]

Sure thing:

1. Install cards
1.2 boot win windows 7 64bit
1.3 Restart once Windows has installed cards
If you already have one card installed with the 10.12 drivers, skip step 2 and follow instructions to activate the new card(s).
2. Install CCC driver suite 10.12
2.2 Restart
3. If second card not there for mining, open device manager and uninstall all four GPU's, but leave the box unchecked to uninstall the driver software
3.2 Restart
4. Windows should re-install all four GPU's with the correct drivers.
5. Restart and begin mining
6. ...Problem Dummy plugs?

[kindle]

So you were saying that during the installation of drivers dont plug in the dummy plugs ?

[ataranlen]

So you were saying that during the installation of drivers dont plug in the dummy plugs ?

I never had to. I only had two monitors running on the first GPU.

[kindle]

Bro thanks for sharing I will try that on the dual 6990 now~!!

[ataranlen]

Bro thanks for sharing I will try that on the dual 6990 now~!!

From what I understand Stream SDK 2.1 (included with 10.12) does not support the 69xx series cards. But this trick might work with other driver versions as well.

[kindle]

Hi bro i just did a round of the things u mentioned and so far no go. it seems like poclbm and diablo miner just freezes at 50% cpu load when ever dual cards of 5970 or 6990 are added to the system without xfire.

I guess i will just xfire and run inefficiently till amd fixes this issue

But thanks for ur guide!