After created tensorflow environment under anaconda, I installed tensorflow-gpu. Then I was trying to import tensorflow to verify if it's correctly installed, but got this error:

ImportError: Could not find 'cudnn64_7.dll'. TensorFlow requires that this DLL be installed in a directory that is named in your %PATH% environment variable. Note that installing cuDNN is a separate step from installing CUDA, and this DLL is often found in a different directory from the CUDA DLLs. You may install the necessary DLL by downloading cuDNN 7 from this URL: https://developer.nvidia.com/cudnn

Setup is:

NVIDIA GTX 1080
CUDA 9.0
cuDNN 6.0
tensorflow-gpu 1.5

Environment Variables are:

CUDA_PAT: C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v9.0
CUDA_PATH_V9_0: C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v9.0

The %Path% variables are:

C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v9.0\bin
C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v9.0\lib\x64
C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v9.0\libnvvp
C:\Users\yshen\AppData\Local\cudnn-8.0-windows10-x64-v6.0\cuda\bin

it is obvious that I installed cuDNN6.0, don't why the error shows "Could not find 'cudnn64_7.dll' ". Why it automatically searches cudnn64_7.dll instead of cudnn64_6.dll?

Also, I got below error when I installed TensorFlow 1.8. I have the Anaconda environment.

"ImportError: Could not find 'cudnn64_7.dll'"

But after I installed Nvidia cuDNN v7.1.3 (April 17, 2018), for CUDA 9.0, everything started to work. Please note that one needs to sign up as a Nvidia developer to be able to download the installation package(s).

Then, just follow the instructions in the page : cudnn-install

For Windows:

3.3. Installing cuDNN on Windows

The following steps describe how to build a cuDNN dependent program. In the following sections:

-your CUDA directory path is referred to as C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v9.0

-your cuDNN directory path is referred to as <installpath>

1. Navigate to your <installpath> directory containing cuDNN.

2. Unzip the cuDNN package. -cudnn-9.0-windows7-x64-v7.zip or -cudnn-9.0-windows10-x64-v7.zip

3. Copy the following files into the CUDA Toolkit directory.

   • Copy <installpath>\cuda\bin\cudnn64_7.dll to C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v9.0\bin.
   • Copy <installpath>\cuda\ include\cudnn.h to C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v9.0\include.
   • Copy <installpath>\cuda\lib\x64\cudnn.lib to C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v9.0\lib\x64.

4. Set the following environment variables to point to where cuDNN is located. To access the value of the $(CUDA_PATH) environment variable, perform the following steps:

   • Open a command prompt from the Start menu.
   • Type Run and hit Enter.
   • Issue the control sysdm.cpl command.
   • Select the Advanced tab at the top of the window.
   • Click Environment Variables at the bottom of the window.
   • Ensure the following values are set: Variable Name: CUDA_PATH Variable Value: C:\Program Files\NVIDIA GPU Computing Toolkit\CUDA\v9.0

5. Include cudnn.lib in your Visual Studio project.

   • Open the Visual Studio project and right-click on the project name.
   • Click Linker > Input > Additional Dependencies.
   • Add cudnn.lib and click OK.