BOINC 6.6.20 x64 does not run on 2 GPUs on Win 7

[efmer (fred)]

There are 2 potential fixes for this and it's not just Windows 7 but x64 Vista as well.

There is a new command on BOINC in cc_config.xml to avoid the incorrect memory sizing on the second GPU or you can add LimitVideoPresentSources to the registry for th card. This stops the need for any dummy VGA adapter etc. The problem I had is due to Vista and Windows 7 only enabling the GPU if there is a device connected to the VGA/DVI port.

The xml to add to cc_config.xml is:-
<cc_config>
<options>
<use_all_gpus>1</use_all_gpus>
</options>
</cc_config>

cc_config.xml file definition is here.
Full solution for LimitVideoPresentSources is at the BOINC Forums

I did all that..(<use_all_gpus>1</use_all_gpus>, plugged in a monitor to the 2e screen, extended the desktop, even tried the registry) but no luck. The card works fine in XP.

[n0xlf]

Also doesn't work for me - BOINC 6.6.36, NVidia 186.18 with 2 GTX280s...Only sees one...Worked fine under Vista 64 bit...

[Raistmer]

If BOINC sees only 1 GPU report this on BOINC site (questions and problems forum).
Also it's worth to search nVidia's forums for known problems with Windows 7.

[n0xlf]

If anyone stumbles on this post, the latest beta 190.38 NVidia drivers fix this issue -
http://www.nvidia.com/Download/Find.aspx?lang=en-us

[efmer (fred)]

If anyone stumbles on this post, the latest beta 190.38 NVidia drivers fix this issue -
http://www.nvidia.com/Download/Find.aspx?lang=en-us

Yes this seems to work. I now See 2 cards on my 295.
But I still had to plug in a second screen.
What I only lack is work...

[n0xlf]

I only have one display plugged in with 2 280s - 295 may be a bit different...

[efmer (fred)]

I only have one display plugged in with 2 280s - 295 may be a bit different...

It seems to work with one as well. But Win 7 been down for some weeks so he request only a max of 10 WU.  Not much to go on.

And of the 10 I got only 2 completed without an error. So that's not very promising.

[efmer (fred)]

I only have one display plugged in with 2 280s - 295 may be a bit different...

It seems to work with one as well. But Win 7 been down for some weeks so he request only a max of 10 WU.  Not much to go on.

And of the 10 I got only 2 completed without an error. So that's not very promising.

This doesn't work with all 295 card, maybe only with certain revisions of the board.