pytorch：测试GPU是否可用

import torch
flag= torch.cuda.is_available()if flag:print("CUDA可使用")else:print("CUDA不可用")

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("驱动为：",device)print("GPU型号： ",torch.cuda.get_device_name(0))

import 	torchimport  timeprint(torch.__version__)print(torch.cuda.is_available())# print('hello, world.')


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

t0= time.time()
c= torch.matmul(a, b)
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)
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))