创建测试结构体

cs
[StructLayout(LayoutKind.Sequential)]
public struct Point
{
    public float X { get; set; }
    public float Y { get; set; }
    public float Z { get; set; }
}

测试函数

这里使用Marshal.PtrToStructure、Span两种方式

cs
    public class Test
    {
        private readonly  IntPtr data;
        private const int count = 2000000;
        public Test()
        {
            var points = new Point[count];
            for (int i = 0; i < points.Length; i++)
            {
                points[i].X = i;
            }
            data = Marshal.AllocHGlobal(points.Length * Marshal.SizeOf(typeof(Point)));

            var ptr = data;
            for (int i = 0; i < points.Length; i++)
            {
                Marshal.StructureToPtr(points[i], ptr, false);
                ptr += Marshal.SizeOf(typeof(Point));
            }
        }
        [Benchmark]
        public  Point[] Method1()
        {
            var points = new Point[count];
            var ptr = data;

            for (int i = 0; i < count; i++)
            {
                points[i] = Marshal.PtrToStructure<Point>(ptr);
                ptr += Marshal.SizeOf(typeof(Point));
            }
            return points;
        }
        [Benchmark]
        public unsafe Point[] Method2()
        {
            var points = new Span<Point>(data.ToPointer(), count);
            return points.ToArray();
        }

    }

结果对比