为什么同一段代码在pycharm和jupyter上的运行结果不一样？

Question

下面是代码：

import time
import torch

def try_gpu(i=0):  #@save
    """如果存在，则返回gpu(i)，否则返回cpu()"""
    if torch.cuda.device_count() >= i + 1:
        return torch.device(f'cuda:{i}')
    return torch.device('cpu')

startTime1=time.time()
for i in range(100):
    A = torch.ones(500,500)
    B = torch.ones(500,500)
    C = torch.matmul(A,B)
endTime1=time.time()

startTime2=time.time()
for i in range(100):
    A = torch.ones(500,500,device=try_gpu())
    B = torch.ones(500,500,device=try_gpu())
    C = torch.matmul(A,B)
endTime2=time.time()

print('cpu计算总时长:', round((endTime1 - startTime1)*1000, 2),'ms')
print('gpu计算总时长:', round((endTime2 - startTime2)*1000, 2),'ms')

pycharm运行结果：

jupyter运行结果：