I'm looking for some help. Sorry for awful english, I'm from Russia.

I have an issue using multiple GPUs on the same computer simultaneously.

BOINC version is 7.2.42. Windows 7 64bit. I'm connected to only one project: SETI@home.

Hardware is:

01.08.2014 14:12:53 | | cc_config.xml not found - using defaults
01.08.2014 14:12:54 | | Starting BOINC client version 7.2.42 for windows_x86_64
01.08.2014 14:12:54 | | log flags: file_xfer, sched_ops, task
01.08.2014 14:12:54 | | Libraries: libcurl/7.25.0 OpenSSL/1.0.1 zlib/1.2.6
01.08.2014 14:12:54 | | Data directory: C:\Program Files\BOINC\tahdata
01.08.2014 14:12:54 | | Running under account User
01.08.2014 14:12:54 | | CUDA: NVIDIA GPU 0: GeForce 210 (driver version 337.88, CUDA version 6.0, compute capability 1.2, 512MB, 453MB available, 67 GFLOPS peak)
01.08.2014 14:12:54 | | CAL: ATI GPU 0: ATI Radeon HD 5400 series (Cedar) (CAL version 1.4.1848, 1024MB, 991MB available, 208 GFLOPS peak)
01.08.2014 14:12:54 | | OpenCL: NVIDIA GPU 0: GeForce 210 (driver version 337.88, device version OpenCL 1.0 CUDA, 512MB, 453MB available, 67 GFLOPS peak)
01.08.2014 14:12:54 | | OpenCL: AMD/ATI GPU 0: ATI Radeon HD 5400 series (Cedar) (driver version 1445.5 (VM), device version OpenCL 1.2 AMD-APP (1445.5), 1024MB, 991MB available, 208 GFLOPS peak)
01.08.2014 14:12:54 | | OpenCL: Intel GPU 0: Intel(R) HD Graphics (driver version 10.18.10.3621, device version OpenCL 1.2, 581MB, 581MB available, 88 GFLOPS peak)
01.08.2014 14:12:54 | | OpenCL CPU: Intel(R) Pentium(R) CPU G3220 @ 3.00GHz (OpenCL driver vendor: Intel(R) Corporation, driver version 3.0.1.10878, device version OpenCL 1.2 (Build 76413))
01.08.2014 14:12:54 | | OpenCL CPU: Intel(R) Pentium(R) CPU G3220 @ 3.00GHz (OpenCL driver vendor: Advanced Micro Devices, Inc., driver version 1445.5 (sse2), device version OpenCL 1.2 AMD-APP (1445.5))
01.08.2014 14:12:54 | | Host name: admin-pc
01.08.2014 14:12:54 | | Processor: 2 GenuineIntel Intel(R) Pentium(R) CPU G3220 @ 3.00GHz [Family 6 Model 60 Stepping 3]
01.08.2014 14:12:54 | | Processor features: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss htt tm pni ssse3 cx16 sse4_1 sse4_2 movebe popcnt syscall nx lm vmx tm2 pbe
01.08.2014 14:12:54 | | OS: Microsoft Windows 7: Enterprise x64 Edition, Service Pack 1, (06.01.7601.00)
01.08.2014 14:12:54 | | Memory: 6.91 GB physical, 6.91 GB virtual
01.08.2014 14:12:54 | | Disk: 80.00 GB total, 53.64 GB free

As you can see I have 3 GPUs of different brands: nvidia, ati and intel. I have one monitor connected to embedded intel's GPU. BOINC is correctly getting and producing tasks for all 3 GPUs. The problem is when I force (using preferences menu) BOINC use GPU, then it uses all 3 of them simultaneously, so I have graphical itches with my Windows 7 GUI. When I set preference to wait some time for inactivity - than BOINC don't use all 3 of the GPU's simultaneously either till that inactivity timer is passed.

That's uncomfortable. Logically I need to force to work just 2 GPUs without monitors: nvidia and ati. And I need to have inactivity timer for GPU with monitor: intel's embedded.

Is it possible to do this using preferences file?

I've read this information:
http://boinc.berkeley.edu/wiki/Client_configuration

Well, there is some interesting options: <ignore_intel_dev> or <exclude_gpu>. So I can force to work 2 GPUs all the time and totally ignore current system's GUI GPU. But it's still not the best solution.

Thank you for any help. If I've missed right place for topic - please forgive me that awful sin.