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I was wondering whether or not I can use a 5770 and a 5830 on guiminer on the same computer.  I can get both to set up separately but together I can only use the one with the primary adapter in ccc.  The other gpu is considered a disabled adapter. 
Iam on windows 7, iam currently running the 5830 on deepbit at 285 or so.

Under Windows you will either need to plug a monitor into each card, use a crossfire cable or there is a hardware trick using a DVI to VGA converter and 3 x 68/75 Ohm resistors (http://www.soerennielsen.dk/mod/VGAdummy/index_en.php) which fools windows into thinking that a monitor is connected.

Tried the dual monitor, got both the screens up but Guiminer only counts the 5830 cypress.  Crossfire I was told is impossible as 5700s and 5800s don't crossfire and the trick sounds about the same as the dual monitor, any other suggestions?

With the second screen attached, did you try reinstalling the drivers, windows is weird like that at times.

Come to think of it, On my Windows machine I couldn't see both my 5870's using phoenix until I enabled crossfire.

With Ubuntu on my second machine I had no issues at all, maybe install Linux ? http://forum.bitcoin.org/index.php?topic=9239.0

Both cards do support OpenCL (http://www.geeks3d.com/20091014/radeon-hd-5770-has-no-double-precision-floating-point-support/).

So any issue in accessing both of them is the windows drivers.

Here is something that I didn't try, installing ATI's OpenCL drivers separate from the version that came with the GPU driver package that I downloaded, maybe that might work for you. http://developer.amd.com/sdks/AMDAPPSDK/downloads/Pages/default.aspx AMD-APP-SDK-v2.4-Windows-64 or AMD-APP-SDK-v2.4-Windows-32

Thanks for the suggestion but eh, sister wanted her monitor back, I'll try it later.  Does anyone have any suggestions for a solo screen comp on how to get these 2 gpus running?  Hmm, I'll try linux I suppose, would rather not have to go through the process of doing all that installing again, so I'll wait until tomorrow if someone puts up a different option. 
Still thanks bert for all the info.

Sorry I couldn't help, hopefully someone who knows more about windows than me can.

Have you tried the dummy plug as previously suggested?  Takes all of 2 minutes to rig one up, if you live in the US and have a radio shack nearby they sell the resistors for .99 for a pack of 5.

http://forums.bit-tech.net/showthread.php?t=167450

here is a simpler solution

http://blog.zorinaq.com/?e=11 (http://blog.zorinaq.com/?e=11)

http://blog.zorinaq.com/images/simple-dummy.jpg

i couldn't find a 75ohm resistor so i tried a 100ohm one and it worked fine.
i had to refresh the displays in ccc.

Alright cool, Ill go buy a risitor later.  Cool thing though, my sister left and I re installed all the drivers, now their both up and running(Thanks bert!).  Thanks for all the help guys.