import torch
flag = torch.cuda.is_available()
print(flag)

ngpu= 1
# Decide which device we want to run on
device = torch.device("cuda:0" if (torch.cuda.is_available() and ngpu > 0) else "cpu")
print(device)
print(torch.cuda.get_device_name(0))
print(torch.rand(3,3).cuda()) 

True
cuda:0
GeForce GTX 1080
tensor([[0.9530, 0.4746, 0.9819],
        [0.7192, 0.9427, 0.6768],
        [0.8594, 0.9490, 0.6551]], device='cuda:0')