我在visualstudio2005环境下编写C#程序，程序中我开了4个线程，每个线程都去调用cuda的dll里边的同一个函数，然后监视运算时间为33秒，作为对比我用单线程我反复的调用该dll里边的那个函数4次，发现用时间为11秒多，为什么多线程反而更耗时？（4核cpu gtx260显卡）
原代码如下：
namespace ThreadTest0406
{
class Program
{
[DllImport(“sumtest.dll”)]
static extern int SUMVALUE();
static int result1, result2, result3, result4;
static void Main(string args)
{
Stopwatch sw = new Stopwatch();
int usetime;
Thread thread1 = new Thread(Fun1);
Thread thread2 = new Thread(Fun2);
Thread thread3 = new Thread(Fun3);
Thread thread4 = new Thread(Fun4);
sw.Reset();
sw.Start();
thread1.Start();
thread2.Start();
thread3.Start();
thread4.Start();
thread1.Join();
thread2.Join();
thread3.Join();
thread4.Join();
sw.Stop();
usetime = (int)sw.ElapsedMilliseconds;
Console.WriteLine(“MultThread:”+usetime.ToString());
sw.Reset();
sw.Start();
result1 = SUMVALUE();
result2 = SUMVALUE();
result3 = SUMVALUE();
result4 = SUMVALUE();
sw.Stop();
usetime = (int)sw.ElapsedMilliseconds;
Console.WriteLine(“SingleThread:”+usetime.ToString());
Console.Read();
}
static void Fun1()
{
result1 = SUMVALUE();
//Console.WriteLine(“result1=” + result1.ToString());
}
static void Fun2()
{
result2 = SUMVALUE();
//Console.WriteLine(“result2=” + result2.ToString());
}
static void Fun3()
{
result3 = SUMVALUE();
//Console.WriteLine(“result3=” + result3.ToString());
}
static void Fun4()
{
result4 = SUMVALUE();
//Console.WriteLine(“result4=” + result4.ToString());
}
}
}