I can detect cuda but cannot use it .so weird

微信图片_20180828221612.jpg960×720 113 KB

my configuration: 1080ti driver:390.77 cuda9.0 cudnn 7.0.5 py3.5
I am sure i correctily installed cuda cause “nvidia-smi” and “nvcc -V” presents normally ,and tensorflow-gpu works well
who can help me!