conda install pytorch torchvision torchaudio cudatoolkit=10.2 -c pytorch

pip install torch===1.5.1 torchvision===0.6.1 -f https://download.pytorch.org/whl/torch_stable.html -i https://pypi.douban.com/simple

conda install pytorch torchvision cudatoolkit=10.2 

conda install --offline 对应的安装包文件名字

conda install cudatoolkit=10.2

# TEST
import torch
from torch.backends import cudnn

x = torch.Tensor([1.0])
xx = x.cuda()
print(torch.__version__)
print(torch.version.cuda)
print(torch.cuda.is_available())
print(xx)
print(cudnn.is_acceptable(xx))

import torch
import time

print(torch.__version__)
print(torch.cuda.is_available())

a = torch.randn(10000, 1000)
b = torch.randn(1000, 2000)

t0 = time.time()
c = torch.matmul(a, b) # 矩阵乘法
t1 = time.time()
print(a.device, t1 - t0, c.norm(2))

t0 = time.time()
c = torch.matmul(a, b) # 矩阵乘法
t1 = time.time()
print(a.device, t1 - t0, c.norm(2))

device = torch.device('cuda')
a = a.to(device)
b = b.to(device)

t0 = time.time()
c = torch.matmul(a, b) # 矩阵乘法
t2 = time.time()
print(a.device, t2 - t0, c.norm(2))

t0 = time.time()
c = torch.matmul(a, b)
t2 = time.time()
print(a.device, t2 - t0, c.norm(2))

import torch
from torch import autograd

x = torch.tensor(1.)
a = torch.tensor(1., requires_grad=True)
b = torch.tensor(2., requires_grad=True)
c = torch.tensor(3., requires_grad=True)

y = a ** 2 * x + b * x + c

print('before:', a.grad, b.grad, c.grad)
grads = autograd.grad(y, [a, b, c])
print('after :', grads[0], grads[1], grads[2])