3x 5850. Only first one recognized by BOINC

lesterhung

Member
Dec 26, 2007
183
0
0
Win7 x64. 11.4 driver.
I used to have only one 5850. Got two more today, and installed it.
BOINC and the Bitcoin miner poclbm says I only have device 0, which is the 5850.
GPU-Z, MSI AfterBurner, and Windows Device Manager all shows 3 GPUs installed.
AMD Vision control shows I have 9 available video outputs, which is correct, 3 for each card, total of 9.

Went into CCC, it says that CrossfireX is not enabled, because I did not install the link cable.
My motherboard is the older MSI K9A2 Platinum with 790 chipset. I don't even know if it supports crossfire.
Even if it did, the Sapphire 5850 Xtreme card I have only have 1 Crossfire link on top, NOT two. So I don't see how I can connect all 3 cards together.

What is causing BOINC and bitcoin miner poclbm to only see device 0?
 

OVerLoRDI

Diamond Member
Jan 22, 2006
5,490
4
81
you need VGA terminators/monitors to enable the cards. Windows will not enable the cards without "displays" plugged in.

Grab a DVI-VGA adapter and a 75ohm (or something close) resistor and put it in the pin #1 and pin #6 on the adapter. Tada fake monitor.

Another idea is if this is a dedicated number cruncher use linux and just use the EXPORT:0 (something along those lines) command, that force enables video cards even without monitors.
 

lesterhung

Member
Dec 26, 2007
183
0
0
you need VGA terminators/monitors to enable the cards. Windows will not enable the cards without "displays" plugged in.

Grab a DVI-VGA adapter and a 75ohm (or something close) resistor and put it in the pin #1 and pin #6 on the adapter. Tada fake monitor.

Another idea is if this is a dedicated number cruncher use linux and just use the EXPORT:0 (something along those lines) command, that force enables video cards even without monitors.

Are you serious? I thought the dummy plugs era has long gone.
I remember having to use those for multiple nVidia 8 and 9 series cards, but later, it was solved with a new driver update.
Since then, I threw away all of my dummy plugs.

Where can I buy resisters locally? Would Radio Shack have them?
Do I need to solder it into the DVI to VGA adapter? Or can I simply insert it into the pins?

Yes, this is a dedicated number cruncher, and I prefer to use Windows. Not familiar with Linux, especially with multiple GPU setups!
 

OVerLoRDI

Diamond Member
Jan 22, 2006
5,490
4
81
then you'll need to make the vga terminators.

Radioshack didn't have 75 ohm 1/2w resistors, so I got 68 ohm resistors and they got the job done.

I didn't solder mine. I just bent it, put on side in the pin 1 and the other side in pin 6. Bent it close then electrical taped over the thing.