C++ 计算总和的多线程程序在笔记本电脑上运行速度比台式机快

作为操作系统课程的一部分，我正在练习多线程程序，并编写了一个非常基本的程序，计算从1到n的和.然而，当我在我的英特尔i5 1035G7笔记本电脑上运行它时，它比我的台式机Ryzen 5 5600G运行得更快，后者应该比我的笔记本电脑强大得多.串行版(只是在没有多线程的情况下将1加到n)在我的PC上运行得更快，所以我真的很困惑为什么多线程版不能.有人能解释一下为什么吗？任何帮助都将不胜感激.

以下是我的程序的基本 struct :

struct threadData
{
    unsigned long long *tempResult;
    long long start;
    long long end;
};

void *calculateTotal(void *arg)
{
    struct threadData *structPtr = (struct threadData *)arg;
    for (long long i = structPtr->start; i <= structPtr->end; i++)
    {
        *(structPtr->tempResult) += i;
    }
    pthread_exit(0);
}

int main(int argc, char *argv[])
{
    ...
    int numThreads = atoi(argv[1]);
    long long input = atoll(argv[2]);
    struct threadData threadDataArray[numThreads];
    unsigned long long result = 0;
    unsigned long long threadResult[numThreads];
    ...
    pthread_t threads[numThreads];

    for (int i = 0; i < numThreads; i++)
    {
        threadDataArray[i].start = i * input / (numThreads) + 1;
        threadDataArray[i].end = (i + 1) * input / (numThreads);
        threadDataArray[i].tempResult = &threadResult[i];
        int threadCreate = pthread_create(&threads[i], NULL, calculateTotal, (void *)&threadDataArray[i]);
        ...
    }
    // wait for all threads to join
    for (int i = 0; i < numThreads; i++)
    {
        int threadJoin = pthread_join(threads[i], NULL);
        ...
    }
    // calculate total
    for (int i = 0; i < numThreads; i++)
    {
        result += threadResult[i];
    }
    printf("(running in parallel)\nsum is: %llu\n", result);
}

我的笔记本电脑上的结果是:

$ time ./ex2parallel 10 4897582469
(running in parallel)
sum is: 11993157022776859215

real    0m9.955s
user    1m0.628s
sys     0m0.010s

我桌面上的结果是:

$ time ./ex2parallel 10 4897582469
(running in parallel)
sum is: 11993157022776859215

real    0m31.003s
user    4m1.410s
sys     0m0.011s 

我在我的笔记本电脑和台式机上都运行了这两个程序，并希望我的Ryzen台式机运行得比我的笔记本电脑好得多.