我编写了一个程序,创建了4个线程,每个线程将20,000个数字从小到大排序50次。我在.NET Core 2.0和.NET Framework 4.6.1上多次运行了此测试。在这个测试中,.NET Framework总是比.NET Core表现更好。
设置
- .NET Core以发布模式发布
- Windows 10,i7双核处理器,4个线程(超线程)
下面的代码用于对比这两个框架。
static void Main()
{
const int amountParallel = 4;
var globalStopwatch = new Stopwatch();
globalStopwatch.Start();
var tasks = new Task<double[]>[4];
for (int i = 0; i < amountParallel; i++)
{
tasks[i] = Start();
}
Task.WaitAll(tasks);
globalStopwatch.Stop();
Console.WriteLine("Averages: {0}ms", tasks.SelectMany(r => r.Result).Average(x => x));
Console.WriteLine("Time completed: {0}", globalStopwatch.Elapsed.TotalMilliseconds);
}
private static Task<double[]> Start()
{
return Task.Factory.StartNew(() =>
{
var numbersToSort = new int[20000];
var globalStopwatch = new Stopwatch();
var individualStopwatch = new Stopwatch();
var stopwatchTimes = new double[50];
int temp;
globalStopwatch.Start();
for (int i = 0; 50 > i; i++)
{
Console.WriteLine("Running task: {0}", i);
numbersToSort = Enumerable.Range(0, 20000).Reverse().ToArray();
individualStopwatch.Start();
for (int indexNumberArray = 0; numbersToSort.Length > indexNumberArray; indexNumberArray++)
{
for (int sort = 0; numbersToSort.Length - 1 > sort; sort++)
{
if (numbersToSort[sort] > numbersToSort[sort + 1])
{
temp = numbersToSort[sort + 1];
numbersToSort[sort + 1] = numbersToSort[sort];
numbersToSort[sort] = temp;
}
}
}
individualStopwatch.Stop();
Console.WriteLine("Task {0} completed, took: {1}ms", i, Math.Round(individualStopwatch.Elapsed.TotalMilliseconds));
stopwatchTimes[i] = individualStopwatch.Elapsed.TotalMilliseconds;
individualStopwatch.Reset();
}
globalStopwatch.Stop();
Console.WriteLine("Total time: {0}s", Math.Round(globalStopwatch.Elapsed.TotalSeconds, 2));
Console.WriteLine("Average: {0}ms", Math.Round(stopwatchTimes.Average(time => time)));
return stopwatchTimes;
}, TaskCreationOptions.LongRunning);
}
测试结果:
.NET Core
- 平均值: 761毫秒
- 总时间: 38秒
.NET Framework
- 平均值: 638毫秒
- 总时间: 32秒
.NET Core不仅在CPU相关任务上较慢,而且在磁盘I/O任务上也较慢。
有任何想法为什么.NET Core在这个部分上稍微慢一些?是否有更改可以提高.NET Core的性能?