title: win10 tensorflow gpu dont work:Device mapping: no known devices
body: <p>I had install:<br>
  1. <strong>cuda_8.0.61_win10.exe</strong><br>
  2. unzip <strong>cudnn-8.0-windows10-x64-v6.0.zip</strong> and copy <strong>.dll、.h、.lib</strong> in <code>bin 、 include、 lib</code> to the path <code>C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v8.0\</code><br>
  3.add <code>C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v8.0\bin</code> to the %PATH%  </p>
  
  <p>but is did`t work when run<br>
  <code>
  Device mapping: no known devices.
  Device mapping: no known devices.
  add_yx: (Add): /job:localhost/replica:0/task:0/cpu:0
  _retval_add_yx_0_0: (_Retval): /job:localhost/replica:0/task:0/cpu:0
  b: (Const): /job:localhost/replica:0/task:0/cpu:0
  a: (Const): /job:localhost/replica:0/task:0/cpu:0
  </code>  </p>
  
  <p>my evn: <strong>win10、gtx970、TensorFlow 1.2</strong><br>
  I had try to reinstall the driver of gtx970, but it still does`t work
  pls help!   </p>
  
  <p><code>
  C:\Users\Wilker&gt;nvcc -V
  nvcc: NVIDIA (R) Cuda compiler driver
  Copyright (c) 2005-2016 NVIDIA Corporation
  Built on Mon_Jan__9_17:32:33_CST_2017
  Cuda compilation tools, release 8.0, V8.0.60
  </code>    </p>
  
  <p><code>
    C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v8.0\extras\demo_suite&gt;deviceQuery.exe
    deviceQuery.exe Starting...
     CUDA Device Query (Runtime API) version (CUDART static linking)
    Detected 1 CUDA Capable device(s)
    Device 0: "GeForce GTX 970"
      CUDA Driver Version / Runtime Version          8.0 / 8.0
      CUDA Capability Major/Minor version number:    5.2
      Total amount of global memory:                 4096 MBytes (4294967296 bytes)
      (13) Multiprocessors, (128) CUDA Cores/MP:     1664 CUDA Cores
      GPU Max Clock rate:                            1266 MHz (1.27 GHz)
      Memory Clock rate:                             3505 Mhz
      Memory Bus Width:                              256-bit
      L2 Cache Size:                                 1835008 bytes
      Maximum Texture Dimension Size (x,y,z)         1D=(65536), 2D=(65536, 65536), 3D=(4096, 4096, 4096)
      Maximum Layered 1D Texture Size, (num) layers  1D=(16384), 2048 layers
      Maximum Layered 2D Texture Size, (num) layers  2D=(16384, 16384), 2048 layers
      Total amount of constant memory:               65536 bytes
      Total amount of shared memory per block:       49152 bytes
      Total number of registers available per block: 65536
      Warp size:                                     32
      Maximum number of threads per multiprocessor:  2048
      Maximum number of threads per block:           1024
      Max dimension size of a thread block (x,y,z): (1024, 1024, 64)
      Max dimension size of a grid size    (x,y,z): (2147483647, 65535, 65535)
      Maximum memory pitch:                          2147483647 bytes
      Texture alignment:                             512 bytes
      Concurrent copy and kernel execution:          Yes with 2 copy engine(s)
      Run time limit on kernels:                     Yes
      Integrated GPU sharing Host Memory:            No
      Support host page-locked memory mapping:       Yes
      Alignment requirement for Surfaces:            Yes
      Device has ECC support:                        Disabled
      CUDA Device Driver Mode (TCC or WDDM):         WDDM (Windows Display Driver Model)
      Device supports Unified Addressing (UVA):      Yes
      Device PCI Domain ID / Bus ID / location ID:   0 / 1 / 0
      Compute Mode:
         &lt; Default (multiple host threads can use ::cudaSetDevice() with device simultaneously) &gt;
    deviceQuery, CUDA Driver = CUDART, CUDA Driver Version = 8.0, CUDA Runtime Version = 8.0, NumDevs = 1, Device0 = GeForce GTX 970
    Result = PASS
  </code></p>