Hello everyone,
Could someone help me resolve the this problem?
I've just built a new PC with the GeForce GTX 680 GPU; installed Windows 7 x64 SP1, all MS updates, latest drivers and BOINC client.
At first, BOINC actually was downloading the tasks for the GPU, but all of them was finished with the "Computation error". Then BOINC stopped even downloading new tasks.
When I updated the nVidia GPU drivers, BOINC downloaded one or more tasks for the GPU and then stopped again.
Tasks for the CPU are being downloaded and completed properly all the time.
BOINC client version is 7.0.28 x64.
Do you have any suggestions on how to fix this?
Thank you.

See NVidia driver problems which cause computation errors over at the Seti forums, which states:

2) Kepler cards unsupported

Drivers affected: All drivers from 304.48 (BETA) onwards.
Hardware affected: nVidia 'Kepler' - GT 6xx and GTX 6xx cards.

Symptom: All tasks end in errors when using the stock v6.10 'cuda_fermi' application.

Solution/workround:
a) Use an optimised Cuda application, where available.
b) Downgrade to the 301.42 driver - only possible on GTX 670/680/690 cards, not on newer releases like the 650/660 or their Ti variants.
c) Set an environment variable, as shown below.

The environment variable to use is

CUDA_GRID_SIZE_COMPAT

and it needs to have the value 1 (one)

You need to be running in Administrator mode, and you need to be running at least driver 306.02 (BETA) or 306.23 (WHQL)

Here's how to reach the setting screen:

Windows 7/Vista:

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