RAID0 SSD阵列写入速度和多线程

Question

我有一个由 20 个 SSD 磁盘组成的 RAID0 阵列，每个 SSD 的最大写入速度为 530 MB/s。PCIexpress 控制器为 8x。

该阵列映射到 Windows 10 中用 NTFS 格式化的虚拟磁盘 (D)

我原本期望我的 C# 应用程序中的写入速度为 7.7 GB/s（PCIExpress 瓶颈会将阵列的 10 GB/s 降低到 20*500MB/s），但使用一个线程我最多只能达到 2.5 GB/S。我的假设完全错误吗？

我还注意到一件事：如果我有一个线程在阵列上写入 127 MB 文件，则平均写入速度为 2.5 GB/s，如果有两个线程，则平均写入速度会下降到 1.8 GB/s。多个线程访问 RAID 阵列可能存在什么问题？

我的代码使用 OpenFileNoBuff 类进行无缓冲写入这里

class Program
{

        const int SIZE = 134184960;
        static string Folder = @"D:\Test";
        static int BlockSize = 65536  ;

        static void Main(string[] args)
        {
            var watchTotal = System.Diagnostics.Stopwatch.StartNew();
            Thread ConsumerThread1 = new Thread(SaveFramesOnDisk);
            Thread ConsumerThread2 = new Thread(SaveFramesOnDisk);

            ConsumerThread1.Start(Folder + "1");
            ConsumerThread2.Start(Folder + "2");

            ConsumerThread1.Join();
            ConsumerThread2.Join();

            watchTotal.Stop();

            long elapsedMs = watchTotal.ElapsedMilliseconds;
            long elapsedS = elapsedMs / 1000;
            Console.WriteLine("TOTAL ELAPSED s: " + elapsedS);
            double gbWritten = 134184960f * 1200 / 1073741824f;
            double avgWriteSpeed = Math.Round(gbWritten / elapsedS,3);
            Console.WriteLine("Avg. write speed GB/s: " + avgWriteSpeed);
        }

        static void SaveFramesOnDisk(object f) 
        {
            //Write 600 frame - 30 seconds acquisition
            for (int i = 0; i < 600; i++)
            {
                
                byte[] data = new byte[SIZE];

                Directory.CreateDirectory(Convert.ToString(f));
                
                //var watchFrame = System.Diagnostics.Stopwatch.StartNew();
                FileStream fs = null;
                OpenFileNoBuff of = null;

                of = new OpenFileNoBuff();
                fs = of.openStream(Path.Combine(Convert.ToString(f), DateTime.Now.ToString("yyyy-MM-dd-HHmmss-fffffff") + ".raw"),
                                    FileMode.Create,
                                    FileAccess.Write,
                                    FileShare.None,
                                    true,
                                    false,
                                    BlockSize);

                //SafeFileHandle handle = File.OpenHandle(Path.Combine(Convert.ToString(f), DateTime.Now.ToString("yyyy-MM-dd-HHmmss-fffffff") + ".raw"), 
                //                                                           FileMode.Create, 
                //                                                           FileAccess.Write, 
                //                                                           FileShare.None, 
                //                                                           FileOptions.Asynchronous, 
                //                                                           SIZE);

                //fs = new FileStream(Path.Combine(Convert.ToString(f), DateTime.Now.ToString("yyyy-MM-dd-HHmmss-fffffff") + ".raw"), FileMode.CreateNew, FileAccess.Write, FileShare.None, 1);
                //fs = new FileStream(handle, FileAccess.Write, 0);

                fs.SetLength(SIZE);

                fs.Write(data, 0, data.Length);
                
                //fs.Flush();
                of.closeStream();
                fs.Close();
                fs.Dispose();
                //watchFrame.Stop();

                //long elapsedFrameMs = watchFrame.ElapsedMilliseconds;

                //Console.WriteLine("elapsedMs for " + i + " write: " + elapsedFrameMs);
                //double time = (double)elapsedFrameMs / 1000;
                //double size = 134184960f / 1073741824f;
                //double speed = size / time;
                //Console.WriteLine("Write speed " + speed + " GB/s");
            }

        }

    }