Guiminer not detecting 2nd graphics card

[Lars]

I just got a 2nd 5970 installed, but guiminer will only let me use two cores for mining. All four cores correctly appear in my device manager, as well as in other tools such as MSI Afterburner. I can get both cards to work individually.

Anyone got any ideas/tricks I can try to get all 4 cores working?

[bitlane]

Not even close to enough info on your part.....

Windows ? Linux ? Dummy Plugs ? Bueller ?

[Jezzz]

Yeah.  Need more info. 

However, cgminer is very good at detecting multiple gpus and setting the best options for them automatically.  You could try that.

[wndrbr3d]

guiminer means he's most likely running windows. if he's running the latest drivers, he won't need dummy plugs to detect 2nd card.

[st4rdust]

Have you got a monitor plugged into your second card? If not, you at least need a "dummy plug" connected to one of its outputs, otherwise the 2nd card will not show up in your mining client. I'm not exactly sure why this is, but I believe it has something to do with the card powering down when it is not tasked with any graphic output workloads.