I have a 9800GX2 card installed, Boinc has no problem recognising the card. SETI@home will runs fine on both GPU's.

I can download a WU for GPUGrid...and run with no problems along side SETI...However...when a 2nd GPUGrid WU is downloaded, this will always fail...but the 1st WU continue without any problems.

So does anyone know why this is?
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Q6600 @ 2.40GHz
Windows 7 - 64bit
8GB RAM
9800GX2 190.62
BOINC 6.10.9 Win64

ACTIVE PROJECTS

Did you ever use beta-managers like 6.6.11/6.6.4 ? What´s about 6.5.0 ?

Anything overclocked, which nvidia driver ?

You are running VIsta, and a GPU card that if I understand the model number has two GPU cores ... so, you should see two GPU tasks running at all times. As shown by:

# Using CUDA device 0
# Device 0: "GeForce 9800 GX2"
# Clock rate: 1500000 kilohertz
# Total amount of global memory: 536870912 bytes
# Number of multiprocessors: 16
# Number of cores: 128
# Device 1: "GeForce 9800 GX2"
# Clock rate: 1500000 kilohertz
# Total amount of global memory: 536870912 bytes
# Number of multiprocessors: 16
# Number of cores: 128


First recommendation, use BOINC Manager 6.5.0 it has caused virtually no issues with GPU Grid from all reports.

Secondly the error is "ERROR: mdsim.cu, line 525: Invalid device selected" which tells me that Vista does not think that the second GPU core has a driver installed. So ... one solution has been to extend the desktop over the second GPU core... since I don't run Vista I have no idea how you do this ... but that is the suggestion from the Vista users ...

IF that does not work you can try to install the driver on the second GPU core.

{edit}
I don't recall what the recommended driver version is for Vista other than it was different than what we suggest for XP ... :)

Have fixed it now...installed lastest Nivida drivers 182.08 and now use boinc 6.6.12
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Q6600 @ 2.40GHz
Windows 7 - 64bit
8GB RAM
9800GX2 190.62
BOINC 6.10.9 Win64

ACTIVE PROJECTS