ubuntu20.04安装cuda11.4以及cudnn

1. 系统：ubuntu20.04
2. 硬件配置：GPU3080、CPU未知
3. 通过《软件和更新》在附加驱动选项中添加了驱动：
   
   1.检查自己电脑支持的cuda

 nvidia-smi

4. 下载cuda11.4.2

wget https://developer.download.nvidia.com/compute/cuda/11.4.2/local_installers/cuda_11.4.2_470.57.02_linux.run
sudo sh cuda_11.4.2_470.57.02_linux.run

会有卡顿，大概等1分钟；因之前安装了驱动，因此在下面的步骤中需要取消安装驱动。

1. Continue
2. accept
3. 取消Driver
   
   
   添加环境变量：

gedit ~/.bashrc
#添加：
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/cuda/lib64
export PATH=$PATH:/usr/local/cuda/bin
export CUDA_HOME=$CUDA_HOME:/usr/local/cuda
#保存退出
source ~/.bashrc

测试CUDA

cd /usr/local/cuda/samples/1_Utilities/deviceQuery
sudo make -j4
./deviceQuery
--------------------------显示-----------------
deviceQuery, CUDA Driver = CUDART, CUDA Driver Version = 11.4, CUDA Runtime Version = 11.4, NumDevs = 1
Result = PASS

安装CUDNN
https://developer.nvidia.com/cudnn （现在需要先登录才能下载）
下载cudnn-linux-x86_64-8.9.7.29_cuda11-archive.tar.xz
下载成功后解压复制

tar zxvf cudnn-11.4-linux-x64-v8.2.4.15.tgz

sudo cp cuda/include/cudnn.h /usr/local/cuda/include/
sudo cp cuda/include/cudnn.h /usr/local/cuda/include/
sudo cp cuda/include/cudnn.h /usr/local/cuda/include/
sudo cp cuda/include/cudnn.h /usr/local/cuda/include/