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janfal
Journeyman III
Journeyman III

CAL cannot find 2nd card on dual hd3870 without monitor attached

Hi,

I have a dual hd3870 machine (crossfire not enabled) running winxp 64 bit. It seems as if the catalyst driver (8.4) will not enable the second card without a monitor attached. calDeviceGetCount is returning 1 with one monitor connected to one of the cards and the other empty. If I connect both cards to monitors Catalyst and CAL both behave as expected (ie both cards appear and calDeviceGetCount returns 2). I managed to get it to work by connecting the second monitor until catalyst enabled the card and then removed it. The device stayed alive for that windows session; however, upon shutdown/restart it disappeared again. I assume it is the autodetect feature, but rather than play tug of war with the driver I figured I would see if anyone else had a similar experience and got it to work permanently. So to sum up, I want 1 monitor with 2 cards enabled without using crossfire.

Thanks in advance
-Jan
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michael_chu
Staff
Staff

CAL cannot find 2nd card on dual hd3870 without monitor attached

Hi Jan,

Unfortunately, the driver currently only enables the card if you do exactly what you did (plug a monitor in during the enabling operation and then you can remove the cable). For the FireStream 9170, the driver will be able to enable the card without a monitor attached.

Now, depending on your monitor, if it has 2 inputs and you normally only use 1 input, this is a trick I used in our labs. I plugged the second card up to the secondary input of the monitor to provide the driver with what it needed.

I haven't tried this myself, but a KVM might do a similar trick (I'm not sure what the KVM sends out on the unselected video port).

Michael.
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mulisak
Journeyman III
Journeyman III

CAL cannot find 2nd card on dual hd3870 without monitor attached

I have recently seen a nice trick which should help

 

http://forum.eeeuser.com/viewtopic.php?id=7562

 

 

 

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michael_chu
Staff
Staff

CAL cannot find 2nd card on dual hd3870 without monitor attached

Clever trick... :)

If someone tries this, can they let me know how it works for them?

Michael.
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