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rainysky
Journeyman III

CAL can not detect all my GPUs.


I got two 5800 series GPU installed on single machine. But the calDeviceGetCount API always return 1, and the calDeviceOpen(&dev, 1) API always fail. Is there any special requirement to use the secondary GPU?

My operating system is windows xp sp3. The SDK is atistream-1.4.0_beta-winxp32.exe and the driver is 9-12_xp32_dd.exe. No display is attached to any of the card.

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Gipsel
Adept I

CAL can not detect all my GPUs.

Originally posted by: rainysky I got two 5800 series GPU installed on single machine. But the calDeviceGetCount API always return 1, and the calDeviceOpen(&dev, 1) API always fail. Is there any special requirement to use the secondary GPU?

My operating system is windows xp sp3. The SDK is atistream-1.4.0_beta-winxp32.exe and the driver is 9-12_xp32_dd.exe. No display is attached to any of the card.



Only the GPU with the primary display (configurable in the display properties) is usable without an attached monitor. Simple solution is to enable Crossfire between the cards. Or you have to usa a VGA dummy.

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emuller
Journeyman III

CAL can not detect all my GPUs.

or to use linux 😉

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empty_knapsack
Adept II

CAL can not detect all my GPUs.

Hmm, can you use 4+ ATI GPUs under linux without any monitor attached? Are they all recognized at least?

 

...Dummy plugs kinda annoys me all the way from XP to Windows 7, may be it's a good idea to build separate machine with linux, hmm...

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nou
Exemplar

CAL can not detect all my GPUs.

yes. thouch there is some issusue with 5970 that second core is still on idle frequency. solution is force 3D clock whole time.

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rainysky
Journeyman III

CAL can not detect all my GPUs.

Will try the VGA dummy solution. Currently I attach a monitor on secondary card and extend the windows desktop to that monitor, after that all cards work properly.

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Gipsel
Adept I

CAL can not detect all my GPUs.

Originally posted by: rainysky Will try the VGA dummy solution. Currently I attach a monitor on secondary card and extend the windows desktop to that monitor, after that all cards work properly.


As I said, just enabling crossfire should do the trick without a secondary display or a dummy plug.

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frankas
Journeyman III

CAL can not detect all my GPUs.

Originally posted by: Gipsel
Originally posted by: rainysky Will try the VGA dummy solution. Currently I attach a monitor on secondary card and extend the windows desktop to that monitor, after that all cards work properly.


 

As I said, just enabling crossfire should do the trick without a secondary display or a dummy plug.

 

Crossfire does not work in Linux, (except maybe for 3D - but not for stream processing purposes). Actually the latest drivers doesn't work without crossfire either, as the primary display goes black. But if you use vnc to enable crossfire, 2 GPUs will be detected. But when you run jobs on both of them, performance is the same as a single GPU.

It would be interesting to know if this works in Windows, and the performance is what you expect from having a multi-GPU setup.

 

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Gipsel
Adept I

CAL can not detect all my GPUs.

Originally posted by: frankasCrossfire does not work in Linux, (except maybe for 3D - but not for stream processing purposes). Actually the latest drivers doesn't work without crossfire either, as the primary display goes black. But if you use vnc to enable crossfire, 2 GPUs will be detected. But when you run jobs on both of them, performance is the same as a single GPU.

It would be interesting to know if this works in Windows, and the performance is what you expect from having a multi-GPU setup.



The thread starter stated that he uses WinXP32

And yes, it works with crossfire enabled. Have it running myself that way (WinXP64) and can load both GPUs independently to 100%. With earlier drivers I observed some performance hit compared to running them as individual cards (~15% for a somewhat memory intense algorithm, looks like some stuff was duplicated on both GPUs or transferred between them). But that has largely disappeared with Catalyst 9.3 or so, at least for me. So the runtime of one kernel on GPU A is not affected if GPU B also runs a kernel or not, the througput simply doubles.

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