When I added a second video card(GT 520) to system, my first video card(GTX 570) is marked as NOT USED during the initialization of BOINC program. BOINC then uses the second video card for the single job.

1/23/2012 12:35:00 PM | | NVIDIA GPU 0 (not used): GeForce GTX 570 (driver version 290.53, CUDA version 4.10, compute capability 2.0, 1280MB, 1118MB available, 1530 GFLOPS peak)
1/23/2012 12:35:00 PM | | NVIDIA GPU 1: GeForce GT 520 (driver version 290.53, CUDA version 4.10, compute capability 2.1, 1024MB, 979MB available, 156 GFLOPS peak)
1/23/2012 12:35:00 PM | | OpenCL: NVIDIA GPU 0 (not used): GeForce GTX 570 (driver version 290.53, device version OpenCL 1.1 CUDA, 1280MB)
1/23/2012 12:35:00 PM | | OpenCL: NVIDIA GPU 1: GeForce GT 520 (driver version 290.53, device version OpenCL 1.1 CUDA, 1024MB)


When I disable the GT 520 via the device manager, BOINC marks the GTX 570 as okay during initialization and uses the video card for the job.

1/23/2012 12:37:59 PM | | NVIDIA GPU 0: GeForce GTX 570 (driver version 290.53, CUDA version 4.10, compute capability 2.0, 1280MB, 1108MB available, 1530 GFLOPS peak)
1/23/2012 12:37:59 PM | | OpenCL: NVIDIA GPU 0: GeForce GTX 570 (driver version 290.53, device version OpenCL 1.1 CUDA, 1280MB)

Currently using version 7.0.8 of BOINC. I don't think the problem occurred when I had a secondary video card of a GT 220.

Currently using version 7.0.8 of BOINC. I don't think the problem occurred when I had a secondary video card of a GT 220.

and what happens when you install Boinc 7.0.11, the latest development version of Boinc?

Claggy

BOINC 7.0.11 also declared the wrong GPU Not Used.

Post your cc_config.xml

I don't know where to find my cc_config.xml. I searched my installed drive and did not find file that file name.

cc_config.xml is an optional configuration file: it will only be present if you created it yourself. If you haven't got one, we can cross it off the list of suspects.

BOINC tries to use the "best" GPU in a system. BOINC's assessment of "best" is done in the '_compare' functions in coproc_detect.cpp. If I'm reading it right, the priority order for NVidia GPUs is:

1) compute capability
2) CUDA version
3) Available memory
4) Speed

In your case, the CC 2.1 GT520 is automatically declared the 'best' above the CC 2.0 GTX570 in the first round of voting: everything else is ignored.

That suggests that the code is working as designed - which isn't the same thing as saying that the design is intuitive, or even the best possible.

As Richard Haselgrove already pointed out... (I didn't scroll down the whole way before I answered ;))

1/23/2012 12:35:00 PM | | NVIDIA GPU 0 (not used): GeForce GTX 570 (driver version 290.53, CUDA version 4.10, compute capability 2.0, 1280MB, 1118MB available, 1530 GFLOPS peak)
1/23/2012 12:35:00 PM | | NVIDIA GPU 1: GeForce GT 520 (driver version 290.53, CUDA version 4.10, compute capability 2.1, 1024MB, 979MB available, 156 GFLOPS peak)

The Compute Capability of the 520 is higher than the one for the 570, which makes the 520 the better GPU.

The source code for coproc_detect.cpp says:

// return 1/-1/0 if device 1 is more/less/same capable than device 2.
// factors (decreasing priority):
// - compute capability
// - software version
// - available memory
// - speed

So, it's correctly chosen.

This value is read from the nvcuda.dll file that came with your drivers, it isn't something that BOINC invents.

---

LOL... Only NVIDIA would mark a $60 dollar GPU higher than the $350 dollar GPU. To alleviate my problem, I bought another GTX 570 SC for SLI and will use it as my secondary video card. Hurt the pocket, but BOINC wins with an additional job with GPU power of 1530 GFLOPS

Thanks for Info

You can tell BOINC which GPU to use by setting up a cc_config.xml file. Look for <use_all_gpus> and <ignore_cuda_dev> or <ignore_nvidia_dev>, respectively (depending on your BOINC version).

Gruß,
Gundolf

You can tell BOINC which GPU to use by setting up a cc_config.xml file. Look for <use_all_gpus> and <ignore_cuda_dev> or <ignore_nvidia_dev>, respectively (depending on your BOINC version).

I used the following configuration file in the BOINC data directory to mark the GT 520 as Not Used:

<cc_config>
<options>
<ignore_nvidia_dev>1</ignore_nvidia_dev>
</options>
</cc_config>

And what happened? Did BOINC use the 570 or were both GPUs not used?

Gruß,
Gundolf

The GT 520 was marked down and the GTX 570 is mark available and used for computation